Samstag, 31. August 2013

Birds of a Feather: Homophily in Social Networks

Birds of a Feather: Homophily in Social Networks
Miller Mc Pherson et al.; 2001


Abstract

Similarity breeds connection. This principle - the homophily principle - structures network ties of every type, including marriage, friendship, work, advice, support, information transfer, exchange, comembership, and other types of relationship. The result is that people’s personal networks are homogeneous with regard to many sociodemographic, behavioral, and intrapersonal characteristics. Homophily limits people’s social worlds in a way that has powerful implications for the information they receive, the attitudes they form, and the interactions they experience. Homophily in race and ethnicity creates the strongest divides in our personal environments, with age, religion, education, occupation, and gender following in roughly that order. Geographic propinquity, families, organizations, and isomorphic positions in social systems all create contexts in which homophilous relations form. Ties between nonsimilar individuals also dissolve at a higher rate, which sets the stage for the formation of niches (localized positions) within social space. We argue for more research on: (a) the basic ecological processes that link organizations, associations, cultural communities, social movements, and many other social forms; (b) the impact of multiplex ties on the patterns of homophily; and (c) the dynamics of network change over time through which networks and other social entities co-evolve.

The Pace of Life under Artificial Selection: Personality, Energy Expenditure, and Longevity Are Correlated in Domestic Dogs

The Pace of Life under Artificial Selection: Personality, Energy Expenditure, and Longevity Are Correlated in Domestic Dogs
Vincent Careau et al.; 2010


Abstract

The domestic dog has undergone extensive artificial selection resulting in an extreme diversity in body size, personality, life-history, and metabolic traits among breeds. Here we tested whether proactive personalities (high levels of activity, boldness, and aggression) are related to a fast “pace of life” (high rates of growth, mortality, and energy expenditure). Data from the literature provide preliminary evidence that artificial selection on dogs (through domestication) generated variations in personality traits that are correlated with life histories and metabolism. We found that obedient (or docile, shy) breeds live longer than disobedient (or bold) ones and that aggressive breeds have higher energy needs than unaggressive ones. These correlations could result from either human preference for particular trait combinations or, more likely, correlated responses to artificial selection on personality. Our results suggest the existence of a general pace-of-life syndrome arising from the coevolution of  personality, metabolic, and life-history traits.

Donnerstag, 29. August 2013

A Twin and Adoption Study of Reading Achievement: Exploration of Shared-Environmental and Gene-Environment-Interaction Effects

A Twin and Adoption Study of Reading Achievement: Exploration of Shared-Environmental and Gene-Environment-Interaction Effects
Robert M Kirkpatrick et al.; 2011
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3130536/


Abstract

Existing behavior-genetic research implicates substantial influence of heredity and modest influence of shared environment on reading achievement and reading disability. Applying DeFries-Fulker analysis to a combined sample of twins and adoptees (N = 4,886, including 266 reading-disabled probands), the present study replicates prior findings of considerable heritability for both reading achievement and reading disability. A simple biometric model adequately described parent and offspring data (combined N = 9,430 parents and offspring) across differing types of families present in the sample Analyses yielded a high heritability estimate (around 0.70) and a negligible shared-environmentality estimate for both reading achievement and reading disability. No evidence of gene × environment interaction was found for parental reading ability and parental educational attainment, the two moderators analyzed.

Mittwoch, 28. August 2013

Foraging and farming as niche construction: stable and unstable adaptations

Foraging and farming as niche construction: stable and unstable adaptations
Peter Rowly-Conwy and Robert Layton; 2011
http://rstb.royalsocietypublishing.org/content/366/1566/849.long


Abstract

All forager (or hunter–gatherer) societies construct niches, many of them actively by the concentration of wild plants into useful stands, small-scale cultivation, burning of natural vegetation to encourage useful species, and various forms of hunting, collectively termed ‘low-level food production’. Many such niches are stable and can continue indefinitely, because forager populations are usually stable. Some are unstable, but these usually transform into other foraging niches, not geographically expansive farming niches. The Epipalaeolithic (final hunter–gatherer) niche in the Near East was complex but stable, with a relatively high population density, until destabilized by an abrupt climatic change. The niche was unintentionally transformed into an agricultural one, due to chance genetic and behavioural attributes of some wild plant and animal species. The agricultural niche could be exported with modifications over much of the Old World. This was driven by massive population increase and had huge impacts on local people, animals and plants wherever the farming niche was carried. Farming niches in some areas may temporarily come close to stability, but the history of the last 11 000 years does not suggest that agriculture is an effective strategy for achieving demographic and political stability in the world's farming populations.

Evolution of lactase persistence: an example of human niche construction

Evolution of lactase persistence: an example of human niche construction
Pascale Gerbault et al.; 2011
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3048992/


Abstract

Niche construction is the process by which organisms construct important components of their local environment in ways that introduce novel selection pressures. Lactase persistence is one of the clearest examples of niche construction in humans. Lactase is the enzyme responsible for the digestion of the milk sugar lactose and its production decreases after the weaning phase in most mammals, including most humans. Some humans, however, continue to produce lactase throughout adulthood, a trait known as lactase persistence. In European populations, a single mutation (−13910*T) explains the distribution of the phenotype, whereas several mutations are associated with it in Africa and the Middle East. Current estimates for the age of lactase persistence-associated alleles bracket those for the origins of animal domestication and the culturally transmitted practice of dairying. We report new data on the distribution of −13910*T and summarize genetic studies on the diversity of lactase persistence worldwide. We review relevant archaeological data and describe three simulation studies that have shed light on the evolution of this trait in Europe. These studies illustrate how genetic and archaeological information can be integrated to bring new insights to the origins and spread of lactase persistence. Finally, we discuss possible improvements to these models.

Dienstag, 27. August 2013

The cognitive niche: Coevolution of intelligence, sociality, and language

The cognitive niche: Coevolution of intelligence, sociality, and language
Steven Pinker; 2010


Abstract

Although Darwin insisted that human intelligence could be fully explained by the theory of evolution, the codiscoverer of natural selection, Alfred Russel Wallace, claimed that abstract intelligence was of no use to ancestral humans and could only be explained by intelligent design. Wallace’s apparent paradox can be dissolved with two hypotheses about human cognition. One is that intelligence is an adaptation to a knowledge-using, socially interdependent lifestyle, the “cognitive niche.” This embraces the ability to overcome the evolutionary fixed defenses of plants and animals by applications of reasoning, including weapons, traps, coordinated driving of game, and detoxification of plants. Such reasoning exploits intuitive theories about different aspects of the world, such as objects, forces, paths, places, states, substances, and other people’s beliefs and desires. The theory explains many zoologically unusual traits in Homo sapiens, including our complex toolkit, wide range of habitats and diets, extended childhoods and long lives, hypersociality, complex mating, division into cultures, and language (which multiplies the benefit of knowledge because know-how is useful not only for its practical benefits but as a trade good with others, enhancing the evolution of cooperation). The second hypothesis is that humans possess an  ability of metaphorical abstraction, which allows them to coopt faculties that originally evolved for physical problem-solving and social coordination, apply them to abstract subject matter, and combine them productively. These abilities can help explain the emergence of abstract cognition without supernatural or exotic evolutionary forces and are in principle testable by analyses of statistical signs of selection in the human genome.

Increasing Heritability of BMI and Stronger Associations With the FTO Gene Over Childhood

Increasing Heritability of BMI and Stronger Associations With the FTO Gene Over Childhood
Clair M A Haworth et al; 2008
http://onlinelibrary.wiley.com/doi/10.1038/oby.2008.434/full


Abstract

The growing evidence of health risks associated with the rise in childhood obesity adds to the urgency of understanding the determinants of BMI. Twin analyses on repeated assessments of BMI in a longitudinal sample of >7,000 children indicated that the genetic influence on BMI becomes progressively stronger, with heritability increasing from 0.48 at age 4 to 0.78 at age 11. In the same large twin sample, the association between a common variant in the FTO gene and BMI increased in parallel with the rise in heritability, going from R2 < 0.001 at age 4 to R2 = 0.01 at age 11. These findings suggest that expression of FTO may become stronger throughout childhood. Increases in heritability may also be due to children increasingly selecting environments correlated with their genetic propensities.

Assortative mating for antisocial behavior: developmental and methodological implications.

Assortative mating for antisocial behavior: developmental and methodological implications.
R F Krueger et al.; May 1998
Behavior Genetics


Abstract

Do people mate assortatively for antisocial behavior? If so, what are the implications for the development and persistence of antisocial behavior? We investigated assortative mating for antisocial behavior and its correlates in a sample of 360 couples from Dunedin, New Zealand. We found substantial assortative mating for self-reports of antisocial behavior per se and for self-reports of couple members' tendencies to associate with antisocial peers (0.54 on average). Perceptions about the likelihood of social sanctions for antisocial behavior (e.g., being caught by the authorities or losing the respect of one's family) showed moderate assortative mating (0.32 on average). However, assortative mating for personality traits related to antisocial behavior was low (0.15 on average). These findings suggest that, whereas assortative mating for many individual-difference variables (such as personality traits) is low, assortative mating for actual antisocial behaviors is substantial. We conclude that future family studies of antisocial behavior should endeavor to measure and understand the influence of assortative mating. In addition, we outline a testable behavior-genetic model for the development of antisocial behavior, in which genes and environments promoting or discouraging antisocial behavior become concentrated within families (due to assortative mating), giving rise to widely varying individual developmental trajectories that are, nevertheless, similar within families.

Heredity grows on you (lecture snapshot)

http://drjamesthompson.blogspot.co.at/2013/08/heredity-grows-on-you-lecture-snapshot.html






















Video of the lecture:

Ten quite interesting things about intelligence test scores. (I. Deary)

Need for cognition and epistemic curiosity

http://mangans.blogspot.co.at/2013/08/need-for-cognition-and-epistemic.html

Montag, 26. August 2013

Resolute ignorance on race and Rushton

Resolute ignorance on race and Rushton
Linda S Gottfredson; 2012


Abstract

I review Rushton’s research on the evolutionary divergence of the three major human lineages. His life-history theory predicts, and his multiple analyses document, a consistent three-way patterning of mean differences among blacks, whites, and East Asians on coevolved sets of morphological, physiological, developmental, psychological, and behavioral traits. I then analyze a typical example of how critics evaluate his work, including the rate at which they cast his scientific hypotheses, methods and conclusions in politically charged language. The set of articles in question, although authored by well-known academics and appearing in a major, peer-reviewed journal, illustrate how mob science works to ‘‘discredit’’ valid research and enforce collective ignorance about entire bodies of evidence. Rushton is a scholar and gentleman but it appears that his critics often act like neither.

Sonntag, 25. August 2013

Using Gottfredson’s Theory of Circumscription and Compromise in Career Guidance and Counseling

Using Gottfredson’s Theory of Circumscription and Compromise in Career Guidance and Counseling
Linda S Gottfredson; 2004


----------------------------------------------------------------------------------
Publications of Linda S Gottfredson:
http://www.udel.edu/educ/gottfredson/reprints/index.html


Steps toward war:

http://mangans.blogspot.co.at/2013/08/steps-toward-war.html

Do People Make Environments or Do Environments Make People?

Do People Make Environments or Do Environments Make People?
David C Rowe; 2001


Abstract

This article discusses the influence of people’s genetic make-up on their mental states of happiness and depression. Contrary to the conventional wisdom, great fortune does not guarantee happiness; neither does great misfortune assure depression. Emotional states are surprisingly immune to “objective” social circumstances. A biological basis for this relative immunity is that people possess biological set points for these emotional states, rendering the effects of most life events transitory. Genotypes also have indirect effects. People react differently to psychological stressors depending on their genotypes. A susceptible person may succumb to depression, whereas a resilient person may remain unaffected. People also expose themselves to different social environments. Exposure to controllable life events is partly a result of genetic predispositions. Consilience requires that this biological individuality be considered in any understanding of human behavior, including the pursuit of happiness.


[See also: http://menghusblog.wordpress.com/2012/12/18/do-people-make-environments-or-do-environments-make-people/ ... found the full version on Meng Hu's page.]

Women in Science

Women in Science: Biological Factors Should Not be Ignored
Kingsley R Browne; 2005
http://papers.ssrn.com/sol3/papers.cfm?abstract_id=877664 (full download)


Abstract

Harvard President Lawrence Summers was repeatedly denounced for suggesting that innate sex differences might be causally related to the scarcity of women in certain scientific fields. Yet data from a variety of fields reveal that Summers's tentative suggestion could legitimately have been stated with much greater force. Sex differences exist in mathematical, spatial, and verbal abilities; "people versus thing orientation;" competitiveness; dominance-seeking; risk preference; and nurturance. These differences appear to be at least in part products of different selective pressures acting on the sexes during our evolutionary history and are proximately mediated by sex hormones acting primarily during fetal development and at and after puberty. 

Cognitive and temperamental sex differences appear to play a substantial role in observed workplace outcomes. The more spatial, mathematical, and abstract a field, the lower the frequency of women tends to be. Moreover, fields in which women are scarce tend to have the lowest social dimension, while those attracting larger numbers of women tend to have higher social content. An analysis that takes into account biological sex differences provides a richer and more plausible account of occupational distributions than one that assumes that no such differences exist.

Samstag, 24. August 2013

Wenn Deutschland vergreist.

Wenn Deutschland vergreist. Streigespräch zwischen Prof. Herwig Birg und dem Soziologen K U Mayer; 2013


Auszüge:

H. Birg: "Deutschland ist das einzige Land in Europa, in dem die ideale Wunschkinderzahl bei einem Durchschnitt von 1,7 liegt, und zwar selbst unter der Voraussetzung, dass der Staat alle Forderungen für die Unterstützung der Familien erfüllt. In dieser Gesellschaft ist der Wunsch nach Kindern mehr und mehr abhandengekommen."

-----

Im Mai lädt Bundeskanzlerin Angela Merkel zum zweiten Demografiegipfel. Was würden Sie ihr raten?

H. Birg: "Sie sollte die Bevölkerung nicht länger in die Irre führen, sondern die Fakten auf den Tisch legen: Deutschland schrumpft, und Zuwanderung ist nicht die Lösung. Deutschland gewinnt keineswegs an Vielfalt, es wird älter, angepasster, eintöniger, ärmer und ungerechter."


[Veröffentlichungen von Prof. Herwig Birg: http://www.herwig-birg.de/]

The General Factor of Personality, BIS–BAS, expectancies of reward and punishment, self-esteem, and positive and negative affect

General Factor of Personality, BIS–BAS, expectancies of reward and punishment, self-esteem, and positive and negative affect
Stephen Erdle, J P Rusthon; 2010


Abstract

In two studies, we explore the neurobiological basis of the General Factor of Personality (GFP) by correlating it with measures of the Behavioral Inhibition System–Behavioral Activation System (BIS–BAS), generalized expectancies of reward and punishment, self-esteem, and positive and negative affect. The GFP was measured by aggregating across the scales of the Big Five Inventory (reverse keying Neuroticism to reflect Emotional Stability). Self-report measures from undergraduate students (Ns = 128, 88) revealed a single GFP dimension with positive loadings on BAS, expectations of reward, self-esteem, and positive affect, and negative loadings on BIS, expectations of punishment, and negative affect. The results were robust, replicating across the studies, the sexes, and after controlling for social desirability. The measures of BIS–BAS, generalized expectancies, self-esteem, and positive and negative affect accounted for 59% and 56% of the variance in the GFP. BIS–BAS may provide a neurobiological basis of the GFP.

Freitag, 23. August 2013

Mind Which Gap? The Selective Concern Over Statistical Sex Disparities

Mind Which Gap? The Selective Concern Over  Statistical Sex Disparities (link for full download)
Kingsley R Browne; 2013


Abstract

Implicit in the materials for this conference is the assumption that any gap that exists between men and women in the workplace (at least if the gap seems to disfavor women) should be eliminated. The question is asked, “how can this gap be explained and rectified?,” implying that “rectification” should follow irrespective of how the gap is explained.

There are many statistical disparities between the sexes in our world, but only some become the subject of widespread concern. Ones that are perceived as favoring men are labeled “gaps,” while those that favor women are simply facts. Outside the workplace, men are arguably disadvantaged in a variety of arenas, whether in terms of health and longevity, crime and violence, domestic relations, or education. In the workplace, men are far more likely than women to be killed and to work long hours. None of these disparities is generally viewed as a “gap” deserving of intervention, however. Men earn a disproportionate number of Ph.Ds in some fields, while women earn a disproportionate number in others. Only the former set of disparities, however, is typically viewed as a “gap.”

Many of the statistical disparities between the sexes in the workplace are a consequence of average sex differences in the choices that men and women make about education, the workplace, and the family. Many of these choices are products, in part, of biologically influenced sex differences in talents, temperament, and tastes (all of which appear to be influenced by testosterone), and they all involve trade-offs.

Sex Differences in Wisconsin Schizotypy Scales—A Meta-analysis

Sex Differences in Wisconsin Schizotypy Scales—A Meta-analysis
Jouko Miettunen and Erika Jääskeläinen; 2010
http://schizophreniabulletin.oxfordjournals.org/content/36/2/347.full


Abstract

Previous single studies have found inconsistent results on sex differences in positive schizotypy, women scoring mainly higher than men, whereas in negative schizotypy studies have often found that men score higher than women. However, information on the overall effect is unknown. In this study, meta-analytic methods were used to estimate sex differences in Wisconsin Schizotypy Scales developed to measure schizotypal traits and psychosis proneness. We also studied the effect of the sample characteristics on possible differences. Studies on healthy populations were extensively collected; the required minimum sample size was 50. According to the results, men scored higher on the scales of negative schizotypy, ie, in the Physical Anhedonia Scale (n = 23 studies, effect size, Cohen d = 0.59z test P < .001) and Social Anhedonia Scale (n = 14, d = 0.44P < .001). Differences were virtually nonexistent in the measurements of the positive schizotypy, ie, the Magical Ideation Scale (n = 29, d = −0.01, P = .74) and Perceptual Aberration Scale (n = 22, d = −0.08, P = .05). The sex difference was larger in studies with nonstudent and older samples on the Perceptual Aberration Scale (d = −0.19 vs d = −0.03, P < .05). This study was the first one to pool studies on sex differences in these scales. The gender differences in social anhedonia both in nonclinical samples and in schizophrenia may relate to a broader aspect of social and interpersonal deficits. The results should be taken into account in studies using these instruments.

Men and Things, Women and People: A Meta-Analysis of Sex Differences in Interests

Men and Things, Women and People: A Meta-Analysis of Sex Differences in Interests
Rong Su et al.; 2009


Abstract

The magnitude and variability of sex differences in vocational interests were examined in the present meta-analysis for Holland’s (1959, 1997) categories (Realistic, Investigative, Artistic, Social, Enterprising, and Conventional), Prediger’s (1982) Things–People and Data–Ideas dimensions, and the STEM (science, technology, engineering, and mathematics) interest areas. Technical manuals for 47 interest inventories were used, yielding 503,188 respondents. Results showed that men prefer working with things and women prefer working with people, producing a large effect size (d = 0.93) on the Things–People dimension. Men showed stronger Realistic (d = 0.84) and Investigative (d = 0.26) interests, and women showed stronger Artistic (d = -0.35), Social (d = -0.68), and Conventional (d = -0.33) interests. Sex differences favoring men were also found for more specific measures of engineering (d = 1.11), science (d = 0.36), and mathematics (d = 0.34) interests. Average effect sizes varied across interest inventories, ranging from 0.08 to 0.79. The quality of interest inventories, based on professional reputation, was not differentially related to the magnitude of sex differences. Moderators of the effect sizes included interest inventory item development strategy, scoring method, theoretical framework, and sample variables of age and cohort. Application of some item development strategies can substantially reduce sex differences. The present study suggests that interests may play a critical role in gendered occupational choices and gender disparity in the STEM fields.

Adult Temperament and Childbearing over the Life Course

Adult Temperament and Childbearing over the Life Course
Markus Jokela et al.; 2010


Abstract

Emerging evidence suggests that temperament may predict childbearing. We examined the association between four temperament traits (novelty seeking, harm avoidance, reward dependence and persistence of the Temperament and Character Inventory) and child-bearing over the life course in the population-based Cardiovascular Risk in Young Finns study (n 1⁄4 1535; 985 women, 550 men). Temperament was assessed when the participants were aged 20–35 and fertility history from adolescence to adulthood was reported by the participants at age 30–45. Discrete-time survival analysis modelling indicated that high childbearing probability was predicted by low novelty seeking (standardized OR 1⁄4 0.92; 95% confidence interval 0.88–0.97), low harm avoidance (OR 1⁄4 0.90; 0.85–0.95), high reward dependence (OR 1⁄4 1.09; 1.03–1.15) and low persistence (OR 1⁄4 0.91; 0.87–0.96) with no sex differences or quadratic effects. These associations grew stronger with increase in numbers of children. The findings were substantially the same in a completely  prospective analysis. Adjusting for education did not influence the associations. Despite its negative association with overall childbearing, high novelty seeking increased the probability of having children in participants who were not living with a partner  (OR 1⁄4 1.29; 1.12–1.49). These data provide novel evidence for the role of temperament in influencing childbearing, and suggest possible weak natural selection of temperament traits in contemporary humans.

Gender differences in self-estimates of general, mathematical, spatial and verbal intelligence: Four meta analyses

Gender differences in self-estimates of general, mathematical, spatial and verbal intelligence: Four meta analyses
Agata Syzmanowicz, Adrian Furnham; October 2011
Learning and Individual Differences


Abstract

Four meta-analyses were conducted to examine the magnitude of sex differences in self-estimates of general, mathematical/logical, spatial and verbal abilities. For all but verbal ability males gave significantly higher self-estimates than did females. The weighted mean effect size d for general intelligence was .37, for mathematical .44, for spatial .43 and for verbal .07. As these were significantly heterogeneous, homogeneity analysis was performed to identify moderating factors. These included age, instruction type, country and dominating author's gender. The outcomes were discussed in terms of possible causes of this phenomenon and some concerns about the interpretation of the results were raised.

The Rediscovery of Human Nature and Human Diversity

The Rediscovery of Human Nature and Human Diversity
Charles Murray; June 2013


[see also: http://darwinianconservatism.blogspot.co.at/2013/07/the-mps-in-galapagos-5-human-nature-and.html]

Mittwoch, 21. August 2013

Children & Play:

Play is what children do. They do not build houses or make tools, and they do not compete for mates. Children are dependent on their parents, who take on the often-burdensome responsibility of feeding, sheltering and protecting their offspring. Children in contemporary culture may seem especially likely to play, where the struggle for survival is not so arduous and the everyday perils not so great. But children's play is not a reward for technological advancement - a luxury for the culturally well-heeled. In fact, children in industrialized and schooled cultures likely have more demands placed on them than children in traditional cultures. Psychologist Yumi Gosso from the University of Sao Paolo in Brazil and her colleagues write that children from hunter-gather societies "neither hunt nor gather, they do not build houses and shelters, they do not cook or clean. In fact, the life of children, at least under 7 years of age, is mostly, if not solely, a playful life. From early morning to bedtime, they play, typically all together." The lives of children in America, Great Britain, and other first-world countries are likely not as playful or carefree as those of some hunter-gatherer children. We restrict and regulate our children's activities more so than parents in traditional cultures, limiting what children do and with whom they do it. And a frequent activity for many children, watching television, is clearly entertainment, but most people would not classify it as play. Nevertheless, despite parental restrictions and not so playful alternative entertainment, preschool children in contemporary societies spend much of their time playing.

David F Bjorklund; 2007
Why youth is not wasted on  the young - Immaturity in Human Development

Know Thyself, But Not Too Well

"Know thyself" would seem to be a good advice, especially when it comes to one's intellect. Adults who are cognizant of their intellectual strong and weak points can organize their lives accordingly, seeking out opportunities to make the best of what they do best and learning to compensate when their natural or acquired talents are less than ideal for a particular task. Such metacognitive skills, as most cognitive skills, improve with age. But intuitively it would seem that, at any age, people in touch with their mental skills would be at an advantage to people who are out of touch. This is likely true in most situations past the age 9 or so, but it does not seem to be the case for young children. Young children's cognitive immaturity with respect to self-knowledge has some advantages. By not knowing what they don't know yet, children attempt tasks that are currently beyond their ken and their physical abilities. Yet, they are frequently unaware of their less-than-stellar performance. As a result, they continue to explore their world, feeling competent and confident, and along the way acquire some useful information that more "in touch" children may have missed because they would be cognizant of their failure ("If at first you don't succeed, quit - don't make a fool of yourself").
Adults do their part to perpetuate young children's feelings of success. Parents, teachers, and even strangers in the grocery store often confirm young children's feelings of accomplishment. Whether adults do this intentionally to bolster children's self-esteem or perceive the attempts of young children as "cute" and thus worthy of praise isn't always clear, but most adults are more than willing to lower standards of success for young children and applaud their attempts at performing "adult" tasks.
Young children expect success, and, as far as they're concerned, they usually achieve it. Such optimistic opinions of their own abilities are easily seen as something children will outgrow. In fact, children do outgrow their very positive and overly optimistic attitude about their own abilities, usually by their third or fourth grades. But their unrealistic optimism is actually something to be valued and protected. Children who believe they are skillful and in control are more apt to act that way. Rather than rudely awakening them to reality, adults can make the most of young children's optimism, encouraging them to practice new skills and praising them for their "success". The bottom line is that children who feel successful in these early years will likely be successful in the long run.

David F Bjorklund; 2007
Why youth is not wasted on  the young - Immaturity in Human Development

[A great book.]

Greater Emphasis on Female Attractiveness in Homo sapiens: A Revised Solution to an Old Evolutionary Riddle

Greater Emphasis on Female Attractiveness in Homo sapiens: A Revised Solution to an Old Evolutionary Riddle
Jonathan Gottschall; 2007


Abstract

Substantial evidence from psychology and cross-cultural anthropology supports a general rule of greater emphasis on female physical attractiveness in Homo sapiens. As sensed by Darwin (1871) and clarified by Trivers (1972), generally higher female parental investment is a key determinant of a common pattern of sexual selection in which male animals are more competitive, more eager sexually and more conspicuous in courtship display, ornamentation, and coloration. Therefore, given the larger minimal and average parental investment of human females, keener physical attractiveness pressure among women has long been considered an evolutionary riddle. This paper briefly surveys previous thinking on the question, before offering a revised explanation for why we should expect humans to sharply depart from general zoological pattern of greater emphasis on male attractiveness. This contribution hinges on the argument that humans have been seen as anomalies mainly because we have been held up to the wrong zoological comparison groups. I argue that humans are a partially sex-role reversed species, and more emphasis on female physical attractiveness is relatively common in such species. This solution to the riddle, like those of other evolutionists, is based on peculiarities in human mating behavior, so this paper is also presented as a refinement of current thinking about the evolution of human mating preferences.

Who Knows What About a Person?

Who Knows What About a Person? The Self–Other Knowledge Asymmetry (SOKA) Model
Simine Vazire; 2010


Abstract

This article tests a new model for predicting which aspects of personality are best judged by the self and which are best judged by others. Previous research suggests an asymmetry in the accuracy of personality judgments: Some aspects of personality are known better to the self than others and vice versa. According to the self– other knowledge asymmetry (SOKA) model presented here, the self should be more accurate  than others for traits low in observability (e.g., neuroticism), whereas others should be more accurate than the self for traits high in evaluativeness (e.g., intellect). In the present study, 165 participants provided self-ratings and were rated by 4 friends and up to 4 strangers in a round-robin design. Participants then  completed a battery of behavioral tests from which criterion measures were derived. Consistent with SOKA model predictions, the self was the best judge of neuroticism-related traits, friends were the best judges of intellect-related traits, and people of all perspectives were equally good at judging extraversion-related traits. The theoretical and practical value of articulating this asymmetry is discussed.

Montag, 19. August 2013

Adaptive Memory: Evolutionary Constraints on Remembering

Adaptive Memory: Evolutionary Constraints on Remembering
James S Nairne; 2010


Abstract

Human memory evolved subject to the constraints of nature’s criterion—differential survival and reproduction. Consequently, our capacity to remember  and forget is likely tuned to solving fitness-based problems, particularly those prominent in the ancestral environments in which memory evolved. Do the operating characteristics of memory continue to bear the footprint of nature’s criterion? This is ultimately an empirical question, and I review evidence consistent with this claim. In addition, I briefly consider several explanatory assumptions of modern memory theory from the perspective of nature’s criterion. How well-equipped is the toolkit of modern memory theory to deal with a cognitive system shaped by nature’s criterion? Finally, I discuss the inherent difficulties that surround evolutionary accounts of cognition. Given there are no fossilized memory traces, and only incomplete knowledge about ancestral environments, is it possible to develop an adequate evolutionary account of remembering?

Effortful Control, Explicit Processing, and the Regulation of Human Evolved Predispositions

Effortful Control, Explicit Processing, and the Regulation of Human Evolved Predispositions
Kevin B MacDonald


Abstract

This article analyzes the effortful control of automatic processing related to social and emotional behavior, including control over evolved modules designed to solve problems of survival and reproduction that were recurrent over evolutionary time. The inputs to effortful control mechanisms include a wide range of nonrecurrent information—information resulting not from evolutionary regularities but from explicit appraisals of costs and benefits. Effortful control mechanisms are associated with the ventro-medial prefrontal cortex and the ventral anterior cingulated cortex. These mechanisms are largely separate from mechanisms of cognitive control (termed executive function) and working memory, and they enable effortful control of behavior in the service of long range goals. Individual differences in effortful control are associated with measures of conscientiousness in the Five Factor Model of personality. Research in the areas of aggression, ethnocentrism, sexuality, reward seeking, and emotion regulation is reviewed indicating effortful control of automatic, implicit processing based on explicit appraisals of the context. Evidence is reviewed indicating that evolutionary pressure for cooperation may be a critical adaptive function accounting for the evolution of explicit processing.

Height, Relationship Satisfaction, Jealousy, and Mate Retention

Height, Relationship Satisfaction, Jealousy, and Mate Retention
Gayle Brewer and Charlene Riley


Abstract

Male height is associated with high mate value. In particular, tall men are  perceived as more attractive, dominant and of a higher status than shorter rivals, resulting in a greater lifetime reproductive success. Female infidelity and relationship dissolution may therefore present a greater risk to short men. It was predicted that tall men would  report greater relationship satisfaction and lower jealousy and mate retention behavior than short men. Ninety eight heterosexual men in a current romantic relationship completed a questionnaire. Both linear and quadratic relationships were found between male height and relationship satisfaction, cognitive and behavioral jealousy. Tall men reported greater relationship satisfaction and lower levels of cognitive or behavioral jealousy than short men. In addition, linear and quadratic relationships were found between male height and a number of mate retention behaviors. Tall and short men engaged in different mate retention behaviors. These findings are consistent with previous research conducted in this area detailing the greater attractiveness of tall men.

Height among Women is Curvilinearly Related to Life History Strategy

Height among Women is Curvilinearly Related to Life History Strategy
Thomas V Pollet at al.; 2009


Abstract

It was hypothesized that women of medium height would show a more secure, long-term mating pattern characterized by less jealousy, less intrasexual competition and a “slower” life history strategy. In three samples of female undergraduate students clear support was found for these hypotheses. In Study 1, among 120 participants, height was curvilinearly related to well-established measures of possessive and reactive jealousy, with women of medium height being less jealous than tall as well as short women. In Study 2, among 40 participants, height was curvilinearly related to intrasexual competition, with women of medium height being less competitive towards other women than tall as well as short women. In Study 3, among 299 participants, height was curvilinearly related to the Mini-K, a well-validated measure of “slower” life history strategy, with women of medium height having a slower life history strategy than tall as well as short women. The results suggest that women of medium height tend to follow a different mating strategy than either tall or short women. Various explanations and implications of these results are discussed.




Is there an early-30s peak in female sexual desire? Cross-sectional evidence from the United States and Canada

Is there an early-30s peak in female sexual desire? Cross-sectional evidence from the United States and Canada
David P Schmitt et al.; 2002


Abstract

This research explored whether women experience a "sexual peak" during their early 30s and, if so, whether such a peak might have an evolved function. In Study 1, results from a cross-sectional sample of US college students (N=803 women, 415 men) revealed that women between 30 and 34, relative to older and younger women, described themselves as more lustful, seductive, and sexually active. In contrast, men did not experience a sexual peak between 30 and 34. In a 2nd study (N=611 women, 329 men), findings of an early-30s peak in women were replicated among married and single individuals from Canada. Using new measures of human sexual strategies, the authors were able to test 2 hypotheses about the possible functions of an early-30s peak in female sexual desire. One hypothesis is that an early-30s peak increases reproduction in monogamous, long-term relationships. A 2nd hypothesis is that women's early-30s peak in sexual desire increases reproduction through promiscuous or extra-pair copulations. Overall, the hypothesis that the peak is designed to increase women's reproduction in monogamous, long-term relationships received the most support. Discussion focuses on limitations and alternative explanations of the current findings and on areas for future investigation.

Freitag, 16. August 2013

Human nature or human natures?

Human nature or human natures?
Peter Frost; 2011


Abstract

Most evolutionary psychologists share a belief in one key concept: the environment of evolutionary adaptedness (EEA), i.e., the ancestral environment that shaped the heritable mental and behavioral traits of present-day humans. It is usually placed in the African savannah of the Pleistocene, long before our ancestors began to spread to other continents some fifty thousand years ago. Thus, later environments have not given rise to new traits through genetic evolution.
This belief rests on two arguments: 1) such traits are complex and therefore evolve too slowly to have substantially changed over the past fifty thousand years; 2) because the same time frame has seen our species diversify into many environments, recent traits should tend to be environment-specific and hence population-specific, yet such specificity  seems inconsistent with the high genetic overlap among human populations. Both arguments are weaker than they seem. New complex traits can arise over a relatively short time through additions, deletions, or modifications to existing complex traits, and genetic overlap can be considerable even between species that are morphologically, behaviorally, and physiologically distinct.
There is thus no conceptual barrier to the existence of EEAs in post-Pleistocene times. Such a paradigm could shed light on such research topics as the visual word form area, reproductive strategy, predisposition to violence among young men, and personality traits. Eventually, a multi-EEA model may dominate evolutionary psychology, perhaps after an interim period of accommodation with the current model.

[See also: http://www.humanbiologicaldiversity.com/]

Literaturhinweise zur Intelligenzforschung:

  • Etwas älter schon, aber immer noch ausgesprochen lesenswert, ist das außergewöhnlich verständlich abgefasste und inhaltlich sehr solide Buch von Jensen (1981, englisch) zu Intelligenztests [Straight Talk about Mental Tests], welches sich expressis verbis an Laien wendet. Über den Stand der Intelligenzforschung informiert allgemeinverständlich Eysencks (2004) posthum erschienenes Buch Die IQ-Bibel. Es ist ebenfalls ein Sachbuch, also auch für Lehrer, Studienanfänger der Pädagogik, interessierte Bildungspolitiker, usw. geeignet. Aber auch Psychologiestudenten und praktizierende Psychologen lesen es mit Gewinn. Lernen macht intelligent - Warum Begabung gefördert werden muss, so heißt das flüssig geschriebene Sachbuch von Neubauer und Stern (2007), in dem auch praktische Schlussfolgerungen aus der Intelligenzforschung für das Lernen in der Schule gezogen werden. Man sollte es sich aber mit einer kritischen Grundhaltung zu Gemüte führen. Und noch etwas für Laien: Die Zeitschrift GEOkompakt hat als Nr. 28 (2011) ein Heft mit dem Titel Intelligenz, Begabung, Kreativität herausgebracht. Es enthält diverse Artikel zum Themenbereich für Nicht-Psychologen.
  • Gelungen ist das im Januar 2012 erschienene Buch von Zimmer Ist Intelligenz erblich? Der ehemalige Wissenschaftsjournalist der ZEIT hat eine rundum gut zu lesende und ausgewogen-kompetente Einführung als Mittelweg zwischen Sach- und Fachbuch geschrieben. Ein sehr schönes Buch, das jeder, der sich fürs Thema interessiert, lesen sollte.
  • Das absolute Standardwerk zur allgemeinen Intelligenz "g", allerdings wirklich nur für Fachleute (Psychologen) geschrieben, stammt von Jensen (1998, englisch) [The g Factor]. Es ist ein Resümee der jahrzehntelangen Forschungsbemühungen und des Erkenntnisstrebens eines weltweit angesehenen Experten. Es enthält zusätzlich zu zahlreichen inhaltlichen Befunden auch viele forschungsmethodische Anmerkungen. Wer sich intensiver mit dem Phänomen der Intelligenz auseinandersetzen will, kann an diesem Buch nicht vorbei gehen. Eine feine Ergänzung ist das 2003 von Nyborg zu Ehren von Jensen editierte Werk The scientific study of general intelligence. Eine Diskussionsgrundlage zu "g" bietet der von Sternberg und Grigorenko (2002, englisch) herausgegebene Band zur Frage, wie generell die generelle Intelligenz ist.
  • Gewissermaßen ein Vorläuferband zu Jensens Wälzer, mit vergleichbarer Zielsetzung und gleichem Titel, aber weniger als halb so umfangreich und auch für Laien verständlich, ist das Buch von Brand (1996, englisch). Dieses Werk ist vom Verlag Wiley aus rein ideologischen Gründen wenige Tage nach dem Druck, aber noch vor der Auslieferung an die Buchhandlungen, zurückgezogen worden. So viel zur Meinungsmanipulation durch Buchfabriken. Aber Wissenschaft lässt sich nicht unterdrücken: Brands Buch kann kostenlos aus dem Netz heruntergeladen werden. Was man auch tun sollte. Sofort!
  • Auch gut konstruierten Intelligenztests wird immer wieder vorgeworfen, sie würden bestimmte gesellschaftliche Gruppen (z.B. Farbige) systematisch benachteiligen, hätten also einen bias. Dieser Vorwurf ist jedoch nicht zutreffend. Der dicke Band von Jensen (1980, englisch)  [Bias in Mental Testing] setzt sich sehr ausführlich mit diesem Problem auseinander. Es dürfte immer noch das weltweit solideste Buch zu diesem Thema sein. Zudem erläutert Jensen auch viele statistische Methoden und Verfahren - man kann also jede Menge lernen. Man sollte besonders aufmerksam die zahlreichen Anmerkungen am Ende eines Kapitels lesen - dort "verstecken" sich viele wichtige Hinweise.
  • Nur für Psychologen mit entsprechenden differentialpsychologischen, diagnostischen und methodischen Kentnissen ist das hervorragende, aber auch sehr anspruchsvolle Buch von Carroll (1993, englisch) [Human Cognitive Abilities] gedacht. Der Autor reanalysiert weit mehr als 400 Faktorenanalysen zur Intelligenz und entwickelt ein aktuelles hierarchisches Intelligenzstrukturmodell, welches einen vorläufigen Schlusspunkt unter fast 100 Jahre Intelligenzforschung setzt. Die besonders inhaltsreichen, von Sternberg (2000, 2011, englisch) sowie Wilhelm und Engle (2005, englisch, besonders empfehlenswert) [Handbook of understanding and measuring intelligence] herausgegebenen Werke zur Intelligenz wenden sich ebenfalls an Fachleute.
  • Die gesellschaftliche Bedeutung der Intelligenz für die USA diskutierten Herrnstein und Murray (1994, englisch) in ihrem Bestseller The bell curve, über in den USA außerordentlich heftig und polemisch gestritten wurde. Man sollte es lesen - und sich dann seine eigene Meinung bilden. Eine in der Diktion sehr klare und provozierende Schrift, Die IQ-Falle, ebenfalls mit gesellschaftspolitischer Zielsetzung verfasst, stammt von Weiss (2000). Der Autor nimmt kein Blatt vor den Mund, fackelt nicht lange und fasst viele heiße Eisen an. Es ist gut zu lesen. Wie bei jedem Buch, so sollte man sich auch hier mit den Inhalten kritisch auseinandersetzen. Wer sich für übergreifende Zusammenhänge, insbesondere über die Rolle der Intelligenz in der Industriegsellschaft, interessiert, der sei auf das neue Buch von Weiss (2012) über Die Intelligenz und ihre Feinde hingewiesen. Wie bei diesem Autor nicht anders zu erwarten, ist auch dieser faktenreiche Band provokant geschrieben.
  • Last, but not least: Jeder Metzger lobt seine Wurst. Deshalb hier noch zwei Hinweise: Das dicke Handbuch Intelligenz (D.H. Rost, 2013) wendet sich vor allem an Studenten und Dozenten. Umfassend und kritisch werden diverse Facetten des Intelligenzbegriffs, klassische Theorien und alternative Modellvorstellungen zur Intelligenz diskutiert. Es behandelt die Trias "g", "Hochbegabung" und "Arbeitsgedächtnis" und enthält Kapitel zu Geschlechts- und Sozialstatusunterschieden, zur Relevanz und zu Korrelaten des IQ, zu biologischen und genetischen Aspekten sowie zur Konstanz und Veränderbarkeit der Intelligenz. Rund 3500 verarbeitete Quellen machen es zu einer Fundgrube für diejenigen, die tiefer in die Materie einsteigen möchten. Als Ergänzung dazu bietet sich Intelligenz, Hochbegabung, Vorschulerziehung, Bildungsbenachteiligung an (D.H. Rost, 2010).

Detlef H Rost; 2013
Interpretation und Bewertung pädagogisch-psychologischer Studien, 3.Auflage
[Rost ist ein außerordentlich fähiger und humorvoller Forscher. Ein sehr gelungenes Buch.]

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siehe auch: http://studgenpol.blogspot.co.at/2013/08/intelligenz-forscher-detlef-rost-gibt.html

Mittwoch, 14. August 2013

The Functions of Language: An Experimental Study

The Functions of Language: An Experimental Study
Gina Redhead & Robin Dunbar; 2013
http://www.epjournal.net/articles/the-functions-of-language-an-experimental-study/


Abstract

We test between four separate hypotheses (social gossip, social contracts, mate advertising and factual information exchange) for the function(s) of language using a recall paradigm. Subjects recalled the social content of stories (irrespective of whether this concerned social behavior, defection or romantic events) significantly better than they did ecological information. Recall rates were no better on ecological stories if they involved flamboyant language, suggesting that, if true, Miller’s “Scheherazade effect” may not be independent of content. One interpretation of these results might be that language evolved as an all-purpose social tool, and perhaps acquired specialist functions (sexual advertising, contract formation, information exchange) at a later date through conventional evolutionary windows of opportunity.






Dienstag, 13. August 2013

Children’s Behavioral Styles at Age 3 Are Linked to Their Adult Personality Traits at Age 26

Children’s Behavioral Styles at Age 3 Are Linked to Their Adult Personality Traits at Age 26
Avshalom Caspi et al.; 2003


Abstract

We observed 1,000 3-year-old children who exhibited five temperament types: Undercontrolled, Inhibited, Confident, Reserved, and Well-adjusted. Twenty-three years later, we reexamined 96% of the children as adults, using multiple methods of comprehensive personality assessment, including both self- and informant-reports. These longitudinal data provide the longest and strongest evidence to date that children’s early-emerging behavioral styles can foretell their characteristic behaviors,  thoughts, and feelings as adults, pointing to the foundations of  the human personality in the early years of life.

Childhood IQ and adult mental disorders: a test of the cognitive reserve hypothesis.

Childhood IQ and adult mental disorders: a test of the cognitive reserve hypothesis.
Koenen KC et al.; 2009
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2705657/



Abstract


Objective
Cognitive reserve has been proposed as important in the etiology of neuropsychiatric disorders. However, tests of the association between premorbid IQ and adult mental disorders other than schizophrenia have been limited and inconclusive. The authors tested the hypothesis that low childhood IQ is associated with increased risk and severity of adult mental disorders.

Method

Participants were members of a representative 1972-1973 birth cohort of 1,037 males and females in Dunedin, New Zealand, who were followed up to age 32 with 96% retention. WISC-R IQ was assessed at ages 7, 9, and 11. Research diagnoses of DSM mental disorders were made at ages 18, 21, 26, and 32.

Results

Lower childhood IQ was associated with increased risk of developing schizophrenia spectrum disorder, adult depression, and adult anxiety. Lower childhood IQ was also associated with greater comorbidity and with persistence of depression; the association with persistence of generalized anxiety disorder was nearly significant. Higher childhood IQ predicted increased risk of adult mania.

Conclusions

Lower cognitive reserve, as reflected by childhood IQ, is an antecedent of several common psychiatric disorders and also predicts persistence and comorbidity. Thus, many patients who seek mental health treatment may have lower cognitive ability; this should be considered in prevention and treatment planning.

Gender Differences in Personality and Interests: When, Where, and Why?

Gender Differences in Personality and Interests: When, Where, and Why?
Richard A Lippa; November 2010
Social and Personality Psychology Compass


Abstract

How big are gender differences in personality and interests, and how stable are these differences across cultures and over time? To answer these questions, I summarize data from two meta-analyses and three cross-cultural studies on gender differences in personality and interests. Results show that gender differences in Big Five personality traits are ‘small’ to ‘moderate,’ with the largest differences occurring for agreeableness and neuroticism (respective ds = 0.40 and 0.34; women higher than men). In contrast, gender differences on the people–things dimension of interests are ‘very large’ (d = 1.18), with women more people-oriented and less thing-oriented than men. Gender differences in personality tend to be larger in gender-egalitarian societies than in gender-inegalitarian societies, a finding that contradicts social role theory but is consistent with evolutionary, attributional, and social comparison theories. In contrast, gender differences in interests appear to be consistent across cultures and over time, a finding that suggests possible biologic influences.

Developmental Gains in Visuospatial Memory Predict Gains in Mathematics Achievement

Developmental Gains in Visuospatial Memory Predict Gains in Mathematics Achievement
Yaoran Li and David C Geary; 2013
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0070160


Abstract

Visuospatial competencies are related to performance in mathematical domains in adulthood, but are not consistently related to mathematics achievement in children. We confirmed the latter for first graders and demonstrated that children who show above average first-to-fifth grade gains in visuospatial memory have an advantage over other children in mathematics. The study involved the assessment of the mathematics and reading achievement of 177 children in kindergarten to fifth grade, inclusive, and their working memory capacity and processing speed in first and fifth grade. Intelligence was assessed in first grade and their second to fourth grade teachers reported on their in-class attentive behavior. Developmental gains in visuospatial memory span (d = 2.4) were larger than gains in the capacity of the central executive (d = 1.6) that in turn were larger than gains in phonological memory span (d = 1.1). First to fifth grade gains in visuospatial memory and in speed of numeral processing predicted end of fifth grade mathematics achievement, as did first grade central executive scores, intelligence, and in-class attentive behavior. The results suggest there are important individual differences in the rate of growth of visuospatial memory during childhood and that these differences become increasingly important for mathematics learning.

Marriage and motherhood are associated with lower testosterone concentrations in women

Marriage and motherhood are associated with lower testosterone concentrations in women
Emily S Barrett et al.; 2012


Abstract

Testosterone has been hypothesized to modulate the trade-off between mating and parenting effort in males. Indeed, evidence from humans and other pair-bonded species suggests that fathers and men in committed relationships have lower testosterone levels than single men and men with no children. To date, only one published study has examined testosterone in relation to motherhood, finding that mothers of young children have lower testosterone than non-mothers. Here, we examine this question in 195 reproductive-age Norwegian women. Testosterone was measured in morning serum samples taken during the early follicular phase of the menstrual cycle, and marital and maternal status were assessed by questionnaire. Mothers of young children (age≤3) had 14% lower testosterone than childless women and 19% lower testosterone than women who only had children  over age 3. Among mothers, age of the youngest child strongly predicted testosterone levels. There was a trend towards lower testosterone among married women compared to unmarried women. All analyses controlled for body mass index (BMI), age, type of testosterone assay, and time of serum sample collection. This is the first study to look at testosterone concentrations in relation to marriage and motherhood in Western women, and it suggests that testosterone may differ with marital and maternal status in women, providing further corroboration of previous findings in both sexes.

Montag, 12. August 2013

The Nature and Nurture of High IQ

The Nature and Nurture of High IQ
An Extended Sensitive Period for Intellectual Development
Angela M Brant et al.; August 2013
Psychological Science


Abstract

IQ predicts many measures of life success, as well as trajectories of brain development. Prolonged cortical thickening observed in individuals with high IQ might reflect an extended period of synaptogenesis and high environmental sensitivity or plasticity. We tested this hypothesis by examining the timing of changes in the magnitude of genetic and environmental influences on IQ as a function of IQ score. We found that individuals with high IQ show high environmental influence on IQ into adolescence (resembling younger children), whereas individuals with low IQ show high heritability of IQ in adolescence (resembling adults), a pattern consistent with an extended sensitive period for intellectual development in more-intelligent individuals. The pattern held across a cross-sectional sample of almost 11,000 twin pairs and a longitudinal sample of twins, biological siblings, and adoptive siblings.

Women Stay Local, Men Go National and Global? Gender Differences in Political Interest

Women Stay Local, Men Go National and Global? Gender Differences in Political Interest
Hilde Coffe; July 2013
Sex Roles


Abstract

This study challenges the idea that women are less interested in politics than men by arguing that women are not less interested in politics but, rather, are interested in different issues. I decompose the concept of general political interest into interest in local, national and international issues and investigate gender differences in interest in these different issues, as well as in politics in general. Ordinary Least Squares (OLS) regression analyses, based on data collected in 2011 (British Participation Survey) on a representative sample of British citizens (N = 1,353), reveal no substantial gender difference in interest in local issues. Once political efficacy is controlled for, however, women are more likely than men to be interested in local issues. Furthermore, women are less likely to be interested in national and international issues, as well as politics in general, than men. Further analyses demonstrate that part of the gap in general political interest may be explained by the fact that interest in politics is primarily understood as interest in national politics, an issue in which men are more likely to be interested than women. In summary, the results highlight the need to clarify the concept of ‘politics’ and to move towards the notion that women and men are interested in different issues, rather than the notion that women are less politically interested than men.

Ages at Which Men and Women Made Their Most Creative Contribution to Civilization:







Full size:
Click on the image



J. D. Matarazzo; 1972
Wechsler's Measurement and Appraisal of Adult Intelligence
(Adapted from H C Lehman, Age and Achievement, 1953)

Sonntag, 11. August 2013

Life history strategy as a longitudinal predictor of relationship satisfaction and dissolution

Life history strategy as a longitudinal predictor of relationship satisfaction and dissolution
Sally G Olderbak, Aurelio Jose Figueredo; 2010
http://www.u.arizona.edu/~ajf/pdf/Olderbak%20&%20Figueredo%202010.pdf


Abstract

The present study tested whether a couple’s shared life history strategy predicts relationship satisfaction longitudinally and relationship dissolution. Through an integration of structural equation modeling and multilevel modeling, we found that a couple’s shared life history strategy: (1) directly predicted their average relationship satisfaction, (2) indirectly predicted the linear change in their relationship satisfaction, (3) indirectly predicted the variability about their average relationship satisfaction, and (4) directly, yet weakly, predicted their likelihood of experiencing relationship dissolution over a one-year period. Couples in a relationship with a slower average life history strategy were more likely to: (1) report higher average levels of relationship satisfaction, (2) have a positive trajectory of relationship satisfaction, (3) have less variability in relationship satisfaction, and (4) were less likely to experience relationship dissolution. This suggests that the influence of life history strategy decreases over the course of the relationship.

The human socio-cognitive niche and its evolutionary origins

The human socio-cognitive niche and its evolutionary origins
Andrew Withen & David Erdal; 2012
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3385679/


Abstract

Hominin evolution took a remarkable pathway, as the foraging strategy extended to large mammalian prey already hunted by a guild of specialist carnivores. How was this possible for a moderately sized ape lacking the formidable anatomical adaptations of these competing ‘professional hunters’? The long-standing answer that this was achieved through the elaboration of a new ‘cognitive niche’ reliant on intelligence and technology is compelling, yet insufficient. Here we present evidence from a diversity of sources supporting the hypothesis that a fuller answer lies in the evolution of a new socio-cognitive niche, the principal components of which include forms of cooperation, egalitarianism, mindreading (also known as ‘theory of mind’), language and cultural transmission, that go far beyond the most comparable phenomena in other primates. This cognitive and behavioural complex allows a human hunter–gatherer band to function as a unique and highly competitive predatory organism. Each of these core components of the socio-cognitive niche is distinctive to humans, but primate research has increasingly identified related capacities that permit inferences about significant ancestral cognitive foundations to the five pillars of the human social cognitive niche listed earlier. The principal focus of the present study was to review and integrate this range of recent comparative discoveries.

Social bonds in birds are associated with brain size and contingent on the correlated evolution of life-history and increased parental investment

Social bonds in birds are associated with brain size and contingent on the correlated evolution of life-history and increased parental investment
Susanne Schultz & Robin Dunbar; April 2010
Biological Journal of the Linnean Society


Abstract

In birds, large brains are associated with a series of population-level phenomena, including invasion success, species richness, and resilience to population decline. Thus, they appear to open up adaptive opportunities through flexibility in foraging and anti-predator behaviour. The evolutionary pathway leading to large brain size has received less attention than behavioural and ecological correlates. Using a comparative approach, we show that, independent of previously recognized associations with developmental constraints, relative brain size in birds is strongly related to biparental care, pair-bonding, and stable social relationships. We also demonstrate correlated evolution between large relative brain size and altricial development, and that the evolution of both traits is contingent on biparental care. Thus, biparental care facilitates altricial development, which permits the evolution of large relative brain size. Finally, we show that large relative brain size is associated with pair-bond strength, itself a likely consequence of cooperation and negotiation between partners under high levels of parental investment. These analyses provide an evolutionary model for the evolution of and prevalence of biparental care, altricial development, and pair-bonding in birds.

Freitag, 9. August 2013

Human populations and the need for novelty and change:

>Just as your experience can influence your innate temperamental inclinations, culture can shape a population's genetic makeup and thus its mores. Conventional wisdom has it that history is driven by social developments, from new technology like the wheel to new political ideas such as democracy. Proponents of the emerging field of biohistory, however, also see nature's hand in the unfolding human narrative. One of their most interesting arguments focuses on the neophiliac 7R allele's [an allele of the dopamine D4 receptor] radically uneven global distribution.
Research conducted at the University of California at Irvine by Robert Moyzis and his collaborators offers a provocative explanation for why some populations around the world have very high incidence of 7R and others, a very low one. A study led by psychologist Chuansheng Chen first posited that the allele began as a "migration gene". Restlessness can be a big benefit in certain situations, and Moyzis, who takes the sudden-and-recent view of behavioral evolution, thinks that the mutation helped Homo sapiens survive and thrive by spurring our vast African exodus to distant parts unknown.
Everyone who carries the 7R gene today, wether a European urbanite, a sub-Saharan villager, or a South American Indian, has essentially the same version, and using standard statistical methods for analyzing DNA sequences, Moyzis determined that 7R probably arose 50 000 to 40 000 years ago, right around the time of the great migrations. Pointing out that the allele is relatively new and that other primates don't have it at all, he says, "To have maintained a significant incidence in the current population, it must have been selected for, because if a mutation have no benefit, evolution will get rid of it."
Studies of populations around the world show that the groups whose forebears stayed closest to our African home at the time of the great migrations have a high incidence of our ancestral DRD4-4 allele, whose strong affinity for dopamine translates into strong regulation of behavioral excitability. In contrast, the descendants of those who traveled the farthest have the greatest frequency of the genetic variants linked to a low affinity for dopamine and robust novelty seeking: 2R, 5R, and especially 7R. As much as 25 percent of the population in much of Europe, as well as their American descendants, carry 7R, but the highest incidence - up to 85 percent in some groups- occurs among the South American Indian tribes who live farthest from Africa in areas such as the Amazon basin.
At first, it's hard to believe the research that shows that the novelty-seeking 7R allele hardly exists in China anymore. Moyzis thinks that it mutated into the much shorter 2R version, which suggests a selection against the most neophiliac variant. The educated guess as to why and how such a genetic shift occurred in China is "cultural selection" by whatever means. (Offering a seemingly tongue-in-cheek example, University of Utah anthropologist and biohistorian Henry Harpending recalls that when he asked a Chinese biogeneticist why the allele had almost disappeared, "without hesitating, the researcher said, 'Oh, we killed all the 7R people.' ") In one scenario, the Asian adventurers who carried the restless allele might have crossed the Bering Strait into the Americas, where its incidence is high. In another proposed by the Moyzis group, as China's society settled into an economy in which many people spent most of the day cultivating rice, a restless mind and an appetite for novelty became drawbacks. Even two thousand years ago, China's mandarin system would have favored the individuals likeliest to get ahead in its bureaucracy, so that unlike his friskier brother, a dutiful son who rose up in the ranks might have acquired multiple wives and produced many offspring.
Whatever its roots in the ancient past, China's traditionally conservative society is very different from, say America's freewheeling, risk-tolerant, inventive culture. In November 2010, the Chinese government, keenly aware of the country's reputation for imitation rather than innovation, announced a program for dramatically increasing its low number of patents. By offering incentives such as cash bonuses and better housing, the leadership hopes to produce more creators of technology like iPad rather than just efficient manufacturers of them.
It may sound politically incorrect, but over the past few thousand years, cultures and their differences appear to have influenced human DNA, especially in Asia. As Harpending puts it, "When I first saw that research relating an interesting and normal behavioral phenotype to a gene difference, I thought myself, 'Pandora's box is open now.' " This phenomenon is all the more fascinating when you consider that although the two populations are now so diametrically different in both 7R's frequency and the agendas of their societies, the New World Indians are thought to be descendants of Asians who migrated there perhaps 12 000 years ago. The same hyper, distractible, risk-taking characteristics associated with the allele that poorly suit traditional Chinese culture can be highly adaptive in other settings, from the Amazon basin to Silicon Valley, where selection could work in 7R's favor.
The history of 7R in China prompts speculation about its future in the increasingly sedentary, screen-oriented, postindustrial West. In our desk-tethered world, it's already hard to believe that it wasn't so long ago in human history that most people, much less small children, weren't expected to spend their days sitting still and concentrating on mental tasks for hours on end. Unlike Amazon tribesmen and rural Ariaals, many young novelty seekers in our urbanized environments lack the legitimate outlets for their high spirits long provided by our species' ancient, traditional pursuits of exploration and hunting. If also poorly raised and immature, they can end up making trouble for themselves and others. As Harpending says, "There are badly behaved kids who will pick up a brick and throw it through a store window, even though they are sure to get caught. It's just a way of relieving their own boredom."...<


New: Understanding Our Need for Novelty and Change
Winifred Gallagher; 2011

Donnerstag, 8. August 2013

Individual differences in pathogen disgust predict men’s, but not women’s, preferences for facial cues of weight

Individual differences in pathogen disgust predict men’s, but not women’s, preferences for facial cues of weight
Claire I Fisher et al.;
6 August 2013; Article in Press
Individual und Personality Differences


Facial adiposity is negatively associated with health.
Men’s pathogen disgust correlated with preference for lower level of facial adiposity.
Attraction to weight cues may help offset the costs of vulnerability to disease.

Abstract

Previous research suggests that people who score higher on measures of pathogen disgust demonstrate (1) stronger preferences for healthy individuals when assessing their facial attractiveness and (2) stronger negative attitudes about obese individuals. The relationship between pathogen disgust and attractiveness judgments of faces differing in cues of weight has yet to be investigated, however. Here we found that men’s, but not women’s, pathogen disgust was positively correlated with their preference for facial cues of lower weight. Moreover, this effect of pathogen disgust was independent of the possible effects of moral and sexual disgust. These data implicate pathogen disgust in individual differences in preferences for facial cues of weight, at least among men, and suggest that the sex-specific effects of pathogen disgust on preferences for facial cues of weight may be different to those previously reported for general negative attitudes about obese individuals.