Donnerstag, 30. Mai 2013

An Evolutionary Perspective on Humor: Sexual Selection or Interest Indication?

An Evolutionary Perspective on Humor: Sexual Selection or Interest Indication?
Norman P Li et al.; 2009
http://www.mysmu.edu/faculty/normanli/lietal2009.pdf


Abstract

Are people who are funny more attractive? Or does being attractive lead people to be seen as funnier? The answer may depend on the underlying evolutionary function of humor. While humor has been proposed to signal “good genes,” the authors propose that humor also functions to indicate interest in social relationships—in initiating new relationships and in monitoring existing ones. Consistent with this interest indicator model, across three studies both sexes were more likely to initiate humor and to respond more positively and consider the other person to be funny when initially attracted to that person. The findings support that humor dynamics —and not just humor displays—influence romantic chemistry for both men and women, suggesting that humor can ultimately function as a strategy to initiate and monitor social relationships. 

 [Humor produces mental pleasures and possesses a social grooming function.]

Samstag, 25. Mai 2013

Sex Differences in Depression

>Girls and women are more prone to depression and anxiety than men (Brody & Hall, 1993). But depression can be more finely differentiated. One form, called interpersonal depression, appears more often in people who are preoccupied with personal relationships and fear abandonment by others. This of course bears a close correspondence with communion (with its emphasis on connectedness to others) and as we could expect, there are  significant sex differences in this form of depression. For excample, among third- to 12th-grade students, girls more often endorse interpersonal symptoms of depression including lonliness, not liking themselves, and wanting more friends (Leadbetter, Blatt, & Quinlan, 1995). (Self-critical depression on the other hand is seen more commonly in people who are preoccupied with issues of self-worth and are practicularly concerned about failing to meet personal goals or appearing incompetent. Predictably, men show greater depressive vulnerability in this area than women.) People who are vulnerable to interpersonal depression also place an intense value on emotional closeness and are preoccupied by fears of being abandoned or neglected in relationships. Because relationships are highly valued, their loss is a severe blow. Girls report more stress than boys in connection with close relationships (Gore, Aseltine, & Colten, 1993) and display stronger associations between stressful relationship events and behavioral problems (Cohen, Gottlieb, Kershner, & Wehrspann, 1985).<


A mind of her own, Anne Campbell, 2013

Donnerstag, 23. Mai 2013

Intellect as distinct from Openness: differences revealed by fMRI of working memory.

Intellect as distinct from Openness: differences revealed by fMRI of working memory.
CG DeYoung et al.; Nov, 2009
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2805551/


Abstract

Relatively little is known about the neural bases of the Big Five personality trait Openness/Intellect. This trait is composed of 2 related but separable aspects, Openness to Experience and Intellect. On the basis of previous behavioral research (C. G. DeYoung, J. B. Peterson, & D. M. Higgins, 2005), the authors hypothesized that brain activity supporting working memory (WM) would be related to Intellect but not to Openness. To test this hypothesis, the authors used functional magnetic resonance imaging (fMRI) to scan a sample of 104 healthy adults as they performed a difficult WM task. Intellect (and not Openness) was found to correlate with WM accuracy and with accuracy-related brain activity, in left lateral anterior prefrontal cortex and posterior medial frontal cortex. Neural activity in these regions mediated the association between Intellect and WM performance, implicating these regions in the neural substrate of Intellect. Intellect was also correlated significantly with scores on tests of intelligence and WM capacity, but the association of Intellect with brain activity could not be entirely explained by cognitive ability.


Who, What, Where, When (and Maybe Even Why)? How the Experience of Sexual Reward Connects Sexual Desire, Preference, and Performance

Who, What, Where, When (and Maybe Even Why)? How the Experience of Sexual Reward Connects Sexual Desire, Preference, and Performance
James G Pfaus et al.; 2012
http://www.recherche.ouvaton.org/telechargement/pfaus_2012.pdf


Abstract

Although sexual behavior is controlled by hormonal and neurochemical actions in the brain , sexual experience induces a degree of plasticity that allows animals to form instrumental and Pavlovian associations that predict sexual outcomes, thereby directing the strength of sexual responding. This review describes how experience with sexual reward strengthens the development of sexual behavior and induces sexually-conditioned place and partner preferences in rats. In both male and female rats, early sexual experience with partners scented with a neutral or even noxious odor induces a preference for scented partners in subsequent choice tests. Those preferences can also be induced by injections of morphine or oxytocin paired with a male rat’s first exposure to scented females, indicating that pharmacological activation of opioid or oxytocin receptors can‘‘stand in’’for the sexual reward-related neurochemical processes normally activated by sexual stimulation. Conversely, conditioned place or partner preferences can be blocked by the opioid receptor antagonist naloxone. A somatosensory cue (a rodent jacket) paired with sexual reward comes to elicit sexual arousal in male rats, such that paired rats with the jacket off show dramatic copulatory deficits. We propose that endogenous opioid activation forms the basis of sexual reward, which also sensitizes hypothalamic and mesolimbic dopamine systems in the presence of cues that predict sexual reward. Those systems act to focus attention on ,and activate goal directed behavior toward, reward-related stimuli. Thus, a critical period exists during an individual’s early sexual experience that creates a‘‘love map’’or Gestalt of features, movements, feelings, and interpersonal interactions associated with sexual reward.

---------


"It is becoming increasingly clear that there is a critical period of sexual behavior development that forms around an individual’s first experiences with sexual arousal and desire, masturbation, orgasm, and sexual intercourse itself. During this period, the sensory and motor mechanics of the behavior become integrated and crystallized along with the development of preferences for ideal activities and physical features of a partner."




The Flynn effect, group differences, and g loadings

The Flynn effect, group differences, and g loadings
Jan te Nijenhuis; July 2013
Personality and Individual Differences
http://www.iapsych.com/iqmr/fe/LinkedDocuments/nijenhuis2013ip.pdf


Abstract

Flynn effect gains are predominantly driven by environmental factors. Might these factors also be responsible for group differences in intelligence? Group differences in intelligence have been clearly shown to strongly correlate with g loadings. The empirical studies on whether the pattern of Flynn effect gains is the same as the pattern of group differences yield conflicting findings. We present new evidence on the topic using a number of datasets from the US and the Netherlands. Score gains and g loadings showed a small negative average correlation. The general picture is now that there is a small, negative correlation between g loadings and Flynn effect gains. It appears that the Flynn effect and group differences have different causes.

Freud’s Follies: Psychoanalysis as religion, cult, and political movement.

Freud’s Follies: Psychoanalysis as religion, cult, and political movement. 
MacDonald, K. B.; 1996
Reprinted in The Encyclopedia of Pseudoscience, Michael Shermer (Ed.); 2002
http://www.csulb.edu/~kmacd/paper-CrewsFreud.html

Mittwoch, 22. Mai 2013

The social and scientific temporal correlates of genotypic intelligence and the Flynn effect

The social and scientific temporal correlates of genotypic intelligence and the Flynn effect
Michael A Woodley; 2012
http://www.gwern.net/docs/2012-woodley.pdf


Abstract

In this study the pattern of temporal variation in innovation rates is examined in the context of Western IQ measures in which historical genotypic gains and losses along with the Flynn effect are considered. It is found that two alternative genotypic IQ estimates based on an increase in IQ from 1455 to 1850 followed by a decrease from 1850 to the present, best fitted the historical growth and decline of innovation rates (r= .876 and .866, N=56 decades). These genotypic IQ estimates were found to be the strongest predictors of innovation rates in regression in which a common factor of GDP (PPP) per capita and Flynn effect gains along with a common factor of illiteracy and homicide rates were also included (β= .706 and .787, N= 51 decades). The strongest temporal correlate of the Flynn effect was GDP (PPP) per capita (r= .930,N= 51 decades). A common factor of these was used as the dependent variable in regression, in which the common factor of illiteracy/homicide rates was the strongest predictor (β=−1.251 and −1.389, N=51 decades). The genotypic IQ estimates were significant negative predictors of the Flynn effect (β=−.894 and −.978, N= 51 decades). These relationships were robust to path analysis. This finding indicates that the Flynn effect, whilst associated with developmental indicators and wealth, only minimally influences innovation rates, which appear instead to be most strongly promoted or inhibited by changes in genotypic intelligence.

Is friendship akin to kinship?

Is friendship akin to kinship?
Joshua M Ackerman et al.; 2007
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3161124/


Abstract

Although unrelated friends are genetically equivalent to strangers, several lines of reasoning suggest that close friendship may sometimes activate processes more relevant to kinship and that this may be especially true for women. We compared responses to strangers, friends, and kin in two studies designed to address distinct domains for which kinship is known to have functional significance: incest avoidance and nepotism. Study 1 examined emotional responses to imagined sexual contact with kin, friends, and strangers. Results revealed that women, compared to men, treated friends more like kin. Study 2 examined benevolent attributions to actual kin, friends, and strangers. Results revealed that women treated friends very much like kin, whereas men treated friends very much like strangers. The current findings support a domain-specific over a domain-general approach to understanding intimate relationships and raise a number of interesting questions about the modular structure of cognitive and affective processes involved in these relationships.

The preferred traits of mates in a cross-national study of heterosexual and homosexual men and women: an examination of biological and cultural influences.

The preferred traits of mates in a cross-national study of heterosexual and homosexual men and women: an examination of biological and cultural influences.
Lippa RA; Arch Sex Behav, 2007 Apr


Abstract

BBC Internet survey participants (119,733 men and 98,462 women) chose from a list of 23 traits those they considered first, second, and third most important in a relationship partner. Across all participants, the traits ranked most important were: intelligence, humor, honesty, kindness, overall good looks, face attractiveness, values, communication skills, and dependability. On average, men ranked good looks and facial attractiveness more important than women did (d = 0.55 and 0.36, respectively), whereas women ranked honesty, humor, kindness, and dependability more important than men did (ds = 0.23, 0.22, 0.18, and 0.15). Sexual orientation differences were smaller than sex differences in trait rankings, but some were meaningful; for example, heterosexual more than homosexual participants assigned importance to religion, fondness for children, and parenting abilities. Multidimensional scaling analyses showed that trait preference profiles clustered by participant sex, not by sexual orientation, and by sex more than by nationality. Sex-by-nation ANOVAs of individuals' trait rankings showed that sex differences in rankings of attractiveness, but not of character traits, were extremely consistent across 53 nations and that nation main effects and sex-by-nation interactions were stronger for character traits than for physical attractiveness. United Nations indices of gender equality correlated, across nations, with men's and women's rankings of character traits but not with their rankings of physical attractiveness. These results suggest that cultural factors had a relatively greater impact on men's and women's rankings of character traits, whereas biological factors had a relatively greater impact on men's and women's rankings of physical attractiveness.

The perception of sexual attractiveness: sex differences in variability.

The perception of sexual attractiveness: sex differences in variability.
Townsend J M, Wasserman T; Archiv Sex Behav, Jun 1997


Abstract

Results of three independent studies supported predictions derived from evolutionary theory: Men's assessments of sexual attractiveness are determined more by objectively assessable physical attributes; women's assessments are more influenced by perceived ability and willingness to invest (e.g., partners' social status, potential interest in them). Consequently, women's assessments of potential partners' sexual attractiveness and coital acceptability vary more than men's assessments. The proposition that polygamous women's assessments of men's sexual attractiveness vary less than those of monogamous women (because the former allegedly are more influenced by target persons' physical attributes) was also tested. In Study 1 male college students showed more agreement than females in their rankings of the sexual attractiveness of opposite-sex target persons. Target persons' flesh and bodily display enhanced this sex difference. In Study 2 men exhibited less variance than did women in their ratings of target persons' acceptability for dating and sexual relations. Women who viewed models described as having low status showed more variability than did women in the high-status condition. In Study 3 women showed more variability than men did in their ratings of 20 opposite-sex celebrities' sexual attractiveness. Studies 2 and 3 included the Sociosexual Orientation Inventory (SOI)-a measure of polygamous attitudes and behavior. Women's SOI scores did not affect the variability of their assessments in either Study 2 or 3. In Study 3 men with low SOI scores showed less variability than did men with high SOI scores. Alternative explanations of the findings are examined. Theoretical and empirical implications are discussed.

A love that doesn’t last: Pornography consumption and weakened commitment to one’s romantic partner

A love that doesn’t last:  Pornography consumption  and weakened commitment to one’s romantic partner
Nathaniel M Lambert et al.; 2012
http://www.fincham.info/papers/2012-porn.pdf


Abstract

We examined whether the consumption of pornography affects romantic relationships, with the expectation that higher levels of pornography consumption would correspond to weakened commitment in young adult romantic relationships. Study 1 (n = 367) found that higher pornography consumption was related to lower commitment, and Study 2 (n = 34) replicated this finding using observational data. Study 3 (n = 20) participants were randomly assigned to either refrain from viewing pornography or to a self-control task. Those who continued using pornography reported lower levels of commitment than control participants. In Study 4 (n = 67), participants consuming higher levels of pornography flirted more with an extradyadic partner during an online chat. Study 5 (n = 240) found that pornography consumption was positively related to infidelity and this association was mediated by commitment. Overall, a consistent pattern of results was found using a variety of approaches including cross-sectional (Study 1), observational (Study 2), experimental (Study 3), and behavioral (Studies 4 and 5) data.

Montag, 20. Mai 2013

How People Make Their Own Environments: A Theory of Genotype --> Environment Effects

How People Make Their Own Environments: A  Theory of Genotype --> Environment Effects
Sandra Scarr and Kathleen McCartney; 1983
http://defiant.ssc.uwo.ca/undergraduate/psych3440g/readings/Scarr198scar_mc.pdf


Abstract

We propose a theory of development in which experience is directed by genotypes. Genotypic differences are proposed to affect phenotypic differences, both directly and through experience, via 3 kinds of genotype --> environment effects: a passive kind, through environments provided by biologically related parents; an evocative kind, through responses elicited by individuals from others; and an active kind, through the selection of different environments by different people. The theory adapts the 3 kinds of genotype-environment correlations proposed by Plomin,  DeFries, and Loehlin in a developmental model that is used to explain results from studies of deprivation, intervention, twins, and families.


The relationships between behavioral addictions and the five-factor model of personality

The relationships between behavioral addictions and the five-factor model of personality
Cecilie Schou Andreassen et al.; 2013
http://akademiai.com/content/1657rv516897x146/fulltext.pdf


Abstract

Aims: Although relationships between addiction and personality have previously been explored, no study has ever simultaneously investigated the interrelationships between several behavioral addictions, and related these to the main dimensions of the five-factor model of personality. 
Methods: In this study, 218 university students completed questionnaires assessing seven different behavioral addictions (i.e., Facebook addiction, video game addiction, Internet addiction, exercise addiction, mobile phone addiction, compulsive buying, and study addiction) as well as an instrument assessing the main dimensions of the five-factor model of personality.
Results: Of the 21 bivariate intercorrelations between the seven behavioral addictions, all were positive (and nine significantly). The results also showed that (i) Neuroticism was positively associated with Internet addiction, exercise addiction, compulsive buying, and study addiction, (ii) Extroversion was positively associated with Facebook addiction, exercise addiction, mobile phone addiction, and compulsive buying, (iii) Openness to experience was negatively associated with Facebook addiction and mobile phone addiction, (iv) Agreeableness was negatively associated with Internet addiction, exercise addiction, mobile phone addiction, and compulsive buying, and (v) Conscientiousness was negatively associated with Facebook addiction, video game addiction, Internet addiction, and compulsive buying and positively associated with exercise addiction and study addiction.
Conclusions: The positive associations between the seven behavioral addictions suggest one or several underlying pathological factors. Hierarchical multiple regressions showed that personality traits explained between 6% and 17% of the variance in the seven behavioral addictions, suggesting that personality to a varying degree explains scores on measures of addictive behaviors.

Deliberate practice: Is that all it takes to become an expert?

Deliberate practice: Is that all it takes to become an expert?
David Z Hambrick et al.; In Press, Available online 15 May 2013
Intelligence


Abstract

Twenty years ago, Ericsson, Krampe, and Tesch-Römer (1993) proposed that expert performance reflects a long period of deliberate practice rather than innate ability, or “talent”. Ericsson et al. found that elite musicians had accumulated thousands of hours more deliberate practice than less accomplished musicians, and concluded that their theoretical framework could provide “a sufficient account of the major facts about the nature and scarcity of exceptional performance” (p. 392). The deliberate practice view has since gained popularity as a theoretical account of expert performance, but here we show that deliberate practice is not sufficient to explain individual differences in performance in the two most widely studied domains in expertise research—chess and music. For researchers interested in advancing the science of expert performance, the task now is to develop and rigorously test theories that take into account as many potentially relevant explanatory constructs as possible.




Full-size image (6 K)
Fig. 1. Average percentage of variance in chess performance explained by deliberate practice, correcting for measurement error variance. The light gray region represents reliable variance explained by deliberate practice; the dark gray region represents reliable variance not explained by deliberate practice.


Full-size image (6 K)
Fig. 3. Average percentage of variance in music performance accounted for by deliberate practice, correcting for measurement error variance. The light gray region represents reliable variance explained by deliberate practice; the dark gray region represents reliable variance not explained by deliberate practice.


[See also: http://mangans.blogspot.co.at/2013/06/practice-counts-somewhat.html]

Disgust as Embodied Moral Judgment

Disgust as Embodied Moral Judgment
Simone Schnall et al; 2008
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2562923/


Abstract

How, and for whom, does disgust influence moral judgment? In 4 experiments participants made moral judgments while experiencing extraneous feelings of disgust. Disgust was induced in Experiment 1 by exposure to a bad smell, in Experiment 2 by working in a disgusting room, in Experiment 3 by recalling a physically disgusting experience, and in Experiment 4 through a video induction. In each case, the results showed that disgust can increase the severity of moral judgments relative to controls. Experiment 4 found that disgust had a different effect on moral judgment than did sadness. In addition, Experiments 2-4 showed that the role of disgust in severity of moral judgments depends on participants’ sensitivity to their own bodily sensations. Taken together, these data indicate the importance - and specificity - of gut feelings in moral judgments.

Dienstag, 14. Mai 2013

Sex Differences in Sex Drive, Sociosexuality, and Height across 53 Nations

Sex Differences in Sex Drive, Sociosexuality, and Height across 53 Nations: Testing Evolutionary and Social Structural Theories
Richard A Lippa; October 2009
Achives of Sexual Behavior


Abstract

By analyzing cross-cultural patterns in five parameters—sex differences, male and female trait means, male and female trait standard deviations—researchers can better test evolutionary and social structural models of sex differences. Five models of biological and social structural influence are presented that illustrate this proposal. Using data from 53 nations and from over 200,000 participants surveyed in a recent BBC Internet survey, I examined cross-cultural patterns in these five parameters for two sexual traits—sex drive and sociosexuality—and for height, a physical trait with a biologically based sex difference. Sex drive, sociosexuality, and height all showed consistent sex differences across nations (mean ds = .62, .74, and 1.63). Women were consistently more variable than men in sex drive (mean female to male variance ratio = 1.64). Gender equality and economic development tended to predict, across nations, sex differences in sociosexuality, but not sex differences in sex drive or height. Parameters for sociosexuality tended to vary across nations more than parameters for sex drive and height did. The results for sociosexuality were most consistent with a hybrid model—that both biological and social structural influences contribute to sex differences, whereas the results for sex drive and height were most consistent with a biological model—that evolved biological factors are the primary cause of sex differences. The model testing proposed here encourages evolutionary and social structural theorists to make more precise and nuanced predictions about the patterning of sex differences across cultures.

Sex Differences in Personality Traits and Gender-Related Occupational Preferences across 53 Nations

Sex Differences in Personality Traits and Gender-Related Occupational Preferences across 53 Nations: Testing Evolutionary and Social-Environmental Theories
Richard A Lippa; June 2010
Archives of Sexual Behavior


Abstract

Using data from over 200,000 participants from 53 nations, I examined the cross-cultural consistency of sex differences for four traits: extraversion, agreeableness, neuroticism, and male-versus-female-typical occupational preferences. Across nations, men and women differed significantly on all four traits (mean ds = −.15, −.56, −.41, and 1.40, respectively, with negative values indicating women scoring higher). The strongest evidence for sex differences in SDs was for extraversion (women more variable) and for agreeableness (men more variable). United Nations indices of gender equality and economic development were associated with larger sex differences in agreeableness, but not with sex differences in other traits. Gender equality and economic development were negatively associated with mean national levels of neuroticism, suggesting that economic stress was associated with higher neuroticism. Regression analyses explored the power of sex, gender equality, and their interaction to predict men’s and women’s 106 national trait means for each of the four traits. Only sex predicted means for all four traits, and sex predicted trait means much more strongly than did gender equality or the interaction between sex and gender equality. These results suggest that biological factors may contribute to sex differences in personality and that culture plays a negligible to small role in moderating sex differences in personality.

Sonntag, 12. Mai 2013

Gender differences in rumination: A meta-analysis

Gender differences in rumination: A meta-analysis
Daniel P Johnson, Mark a Whisman; 2013
Personality and Individual Differences, Article in Press


Abstract

Starting in adolescence and continuing through adulthood, women are twice as likely as men to experience depression. According to the response styles theory (RST), gender differences in depression result, in part, from women’s tendency to ruminate more than men. A meta-analysis was performed to evaluate gender differences in rumination in adults (= 59; = 14,321); additionally, an analysis of subtypes of rumination – brooding and reflection – was conducted (= 23). Fixed effects analyses indicated that women scored higher than men in rumination (d = .24, p < .01, SEd = .02), brooding (d = .19, p < .01, SEd = .03) and reflection (d = .17, p < .01, SEd = .03); there was no evidence of heterogeneity or publication bias across studies for these effect sizes. Although statistically significant, the effect sizes for gender differences in rumination were small in magnitude. Results are discussed with respect to the RST and gender differences in depression.

Freitag, 10. Mai 2013

Heritability of Verbal and Performance Intelligence in a Pediatric Longitudinal Sample

Heritability of Verbal and Performance Intelligence in a Pediatric Longitudinal Sample
Inge L C van Soelen et al.; 2011
http://www.tweelingenregister.org/nederlands/verslaggeving/NTR-publicaties_2011/Soelen_TRHG_2011.pdf


Abstract

The longitudinal stability of IQ is well-documented as is its increasing heritability with age. In a longitudinal twin study, we addressed the question to what extent heritability and stability differ for full scale (FSIQ), verbal (VIQ), and performance IQ (PIQ) in childhood (age 9–11 years), and early adolescence (age 12–14 years). Genetic and environmental influences and correlations over time were evaluated in an extended twin design, including Dutch twins and their siblings. Intelligence was measured by the Wechsler Intelligence Scale for children — Third version (WISC III). Heritability in childhood was 34% for FSIQ, 37% for VIQ, and 64% for PIQ, and increased up to 65%, 51%, and 72% in early adolescence. The influence of common environment decreased between childhood and early adolescence from explaining 43% of the phenotypic variance for FSIQ to 18% and from 42% for VIQ to 26%. For PIQ common environmental influences did not play a role, either in childhood or in early adolescence. The stability in FSIQ and VIQ across the 3-year interval (rp) was .72 for both measures and was explained by genetic and common environmental correlations across time (FSIQ, rg = .96, rc= 1.0; VIQ, rg=.78, rc= 1.0). Stability of PIQ (rp=.56) was lower and was explained by genetic influences (rg= .90). These results confirm the robust findings of increased heritability of general cognitive abilities during the transition from childhood to adolescence. Interestingly, results for PIQ differ from those for FSIQ and VIQ, in that no significant contribution of environment shared by siblings from the same family was detected.

Efficiency of Functional Brain Networks and Intellectual Performance

Efficiency of Functional Brain Networks and Intellectual Performance
Martijn P van den Heuvel et al.; 2009
http://www.jneurosci.org/content/29/23/7619.full


Abstract

Our brain is a complex network in which information is continuously processed and transported between spatially distributed but functionally linked regions. Recent studies have shown that the functional connections of the brain network are organized in a highly efficient small-world manner, indicating a high level of local neighborhood clustering, together with the existence of more long-distance connections that ensure a high level of global communication efficiency within the overall network. Such an efficient network architecture of our functional brain raises the question of a possible association between how efficiently the regions of our brain are functionally connected and our level of intelligence. Examining the overall organization of the brain network using graph analysis, we show a strong negative association between the normalized characteristic path length λ of the resting-state brain network and intelligence quotient (IQ). This suggests that human intellectual performance is likely to be related to how efficiently our brain integrates information between multiple brain regions. Most pronounced effects between normalized path length and IQ were found in frontal and parietal regions. Our findings indicate a strong positive association between the global efficiency of functional brain networks and intellectual performance.

The genetics of general knowledge: A twin study from Croatia

The genetics of general knowledge: A twin study from Croatia
Dennis Bratko et al.; 2010
Personality and Individual Differences


Abstract

The purpose of this study was to explore genetic and environmental influences on general knowledge (GK) and its relationship with intelligence. The sample consisted of 71 MZ and 78 DZ twin pairs, aged on average 17 years. General knowledge was measured with a test consisting of 60 items measuring different domains of GK including geography, history, politics, art, science, fashion, and sport. Four different measures of intelligence were used, two that measured spatial abilities (visualization and spatial orientation) and two that measured verbal abilities (word fluency and vocabulary). Univariate analyses indicated that the heritability of GK is .87, while heritability estimates for cognitive ability measures ranged from .48 to .73. Bivariate analyses between each of the four intelligence measures and GK measure were carried out using correlated factors model. Shared genetic influences were found between GK and all four intelligence measures in the .40–.80 range.

Mittwoch, 8. Mai 2013

Beyond the Threshold Hypothesis: Even Among the Gifted and Top Math/Science Graduate Students, Cognitive Abilities, Vocational Interests, and Lifestyle Preferences Matter for Career Choice, Performance, and Persistence

Beyond the Threshold Hypothesis: Even Among the Gifted and Top Math/Science Graduate Students, Cognitive Abilities, Vocational Interests, and Lifestyle Preferences Matter for Career Choice, Performance, and Persistence
K F Robertson et al.; 2010
https://my.vanderbilt.edu/smpy/files/2013/02/Ferriman_20101.pdf


Abstract

The assertion that ability differences no longer matter beyond a certain threshold is inaccurate. Among young adolescents in the top 1% of quantitative reasoning ability, individual differences in general cognitive ability level and in specific cognitive ability pattern (that is, the relationships among an individual’s math, verbal, and spatial abilities) lead to differences in educational, occupational, and creative outcomes decades later. Whereas ability level predicts the level of achievement, ability pattern predicts the realm of achievement. Adding information on vocational interests refines prediction of educational and career choices. Finally, lifestyle preferences relevant to career choice, performance, and persistence often change between ages 25 and 35. This change results in sex differences in preferences, which likely have relevance for understanding the underrepresentation of women in careers that demand more than full-time (40 hours per week) commitment.

Constructs of social and emotional effectiveness: Different labels, same content?

Constructs of social and emotional effectiveness: Different labels, same content?
Katja Schlegel et al.; 2013
Journal of Research in Personality


Abstract

Social skills, interpersonal competence, political skill, emotional intelligence, empathy, and emotion recognition ability all belong to the domain of social and emotional effectiveness constructs (SEECs). To date, it remains unclear to what extent SEECs overlap and differ and how they fit in the nomological net of personality. We examined the overall dimensional structure of 32 scales from five self-report and three performance-based instruments, representing the above-mentioned constructs. Four components, namely Expressivity, Sensitivity, Emotional Abilities, and Self-Control, were identified and correlated meaningfully with the Big Five. Trait emotional intelligence and other self-reported SEECs overlapped largely rather than measuring separate constructs. This study provides the basis for a taxonomy of SEECs that will help integrating previous and future research in this domain.

[Not only multiple intelligences, but also multiple (hyper-redundant) emotional intelligences spread out of the ground like flowers.]

Montag, 6. Mai 2013

Who discovered the Flynn Effect? A review of early studies of the secular increase of intelligence

Who discovered the Flynn Effect? A review of early studies of the secular increase of intelligence
Richard Lynn; 2013 (article in press)
Intelligence


Abstract

Flynn has been credited with having discovered the increase in IQs that have been reported in a number of countries during most of the twentieth century and that have come to be known as “the Flynn effect”. This paper documents and discusses a number of reports of increases in IQs that were published from 1936 onwards before the phenomenon was rediscovered by Flynn (1984, 1987). These early reports showed that the Flynn effect is fully present in pre-school children, does not increase during the school age years, and is greater for non-verbal abilities than for verbal abilities.
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"The term “the Flynn effect” was coined by Herrnstein and Murray (1994, p.307) to designate the increases in IQs during the twentieth century that were documented for the United States and for a number of other countries by Flynn (1984,1987). This designation has led many to believe that it was Flynn who discovered the phenomenon. Thus, the rise of IQs “has been called the Flynn effect after its discoverer” (Newcombe, 2007, p. 74); “Flynn's discovery” (Zhu & Tulsky,1999, p.1,255); “Flynn, a New Zealand psychologist who discovered that IQ scores are inflating over time” (Syed, 2007,p.17); and “the insight that made him famous…intelligence scores are rising, James R. Flynn has discovered” (Holloway,1999, p.3). These attributions are misplaced. There were numerous reports of secular increases in intelligence during the half century before they were rediscovered by Flynn (1984). The first objective of this paper is to summarize these early and largely forgotten studies. Who knows today of the work of Runquist (1936), who first discovered the effect? Or of Roesell (1937), Johnson (1937), Wheeler (1942) or Smith (1942) who published early reports on this phenomenon? None of these names appear in textbooks on intelligence such as those of Brody (1992), Sternberg (2000), Hunt (2011), Mackintosh (2011) and Sternberg and Kaufman (2011), or even in books wholly devoted to the Flynn effect by Neisser (1998) and Flynn (2007). The second objective of this paper is to discuss the implications that can be drawn from these early studies."


"Because all the important features of the increase had been reported many years before Flynn's studies, it is difficult to find any justification for designating the phenomenon “the Flynn effect”. In the history of science it is customary to name phenomena after those who first identified them, e.g. Boyle's law, the Heisenberg indeterminacy principle, and the Doppler effect. The first to report the secular increase in intelligence was Runquist (1936) and therefore the proper designation should surely be “the Runquist effect"."

Social Perception of Facial Resemblance in Humans

Social Perception of Facial Resemblance in Humans
Lisa M De Bruine et al.; 2008
http://facelab.org/debruine/Teaching/EvPsych/files/DeBruine_2008.pdf


Abstract

Two lines of reasoning predict that highly social species will have mechanisms to influence behavior toward individuals depending on their degree of relatedness. First, inclusive fitness theory leads to the prediction that organisms will preferentially help closely related kin over more distantly related individuals. Second, evaluation of the relative costs and potential benefits of inbreeding suggests that the degree of kinship should also be considered when choosing a mate. In order to behaviorally discriminate between individuals with different levels of relatedness, organisms must be able to discriminate cues of kinship. Facial resemblance is one such potential cue in humans. Computer-graphic manipulation of face images has made it possible to experimentally test hypotheses about human kin recognition by facial phenotype matching. We review recent experimental evidence that humans respond to facial resemblance in ways consistent with inclusive fitness theory and considerations of the costs of inbreeding, namely by increasing prosocial behavior and positive attributions toward self-resembling images and selectively tempering attributions of attractiveness to other-sex faces in the context of a sexual relationship.

Sonntag, 5. Mai 2013

Energetic demand of multiple dependents and the evolution of slow human growth

Energetic demand of multiple dependents and the evolution of slow human growth
Michael Gurven and Robert Walker; 2006
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1560216/


Abstract

This study investigates the consequences of the human foraging niche and multiple dependent offspring on the optimal growth trajectory of humans. We test the hypothesis that the human pattern of slow human growth between age at weaning and puberty helps defer the compound energetic demand on parents with multiple dependents, by using growth and demographic data from two foraging societies, the Ache of eastern Paraguay and the Dobe Ju/'hoansi of Botswana and Namibia. We run simulations of observed and potential growth trajectories among sub-adults and their consequent energetic demands on parents given profiles of fertility, mortality, consumption and production. We find that either sub-adult production or food subsidies from other people must substantially increase in order to compensate for the dramatic increase in energetic demand on parents if offspring were to grow faster at younger ages. Our conclusion is that slow human growth followed by a rapid adolescent growth spurt may have facilitated rising human fertility rates and greater investments in neural capital.


Fig.1.:  

Samstag, 4. Mai 2013

The Central Six:

In "Spent." Geoffrey Miller wrote a few introducing pages on the "Central Six". The following is an excerpt of these lively formulated pages:

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A century of psychology has identified six major dimensions of variation that predict human behavior and that are salient to us. These are the key individual differences that distinguish human minds. These are the mental traits that can be measured with good reliability and validity, that are genetically heritable and stable across the life span, that predict behavior across diverse settings and domains (school, work, leisure, consumption, and family life) and that seem to be universal across cultures and even across many animal species. If you know how somebody scores on each of the "Central Six" traits, you can infer a lot about his character, capabilities, virtues, and vices.
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G is for general intelligence, the first of the Central Six traits. It is also known as smarts, brains, general cognitive ability, or IQ. Shortly after Charles Spearman's key work in 1904, intelligence became the best-studied, best-established trait in psychology. Higher intelligence predicts higher average success in every domain of life: school, work, money, mating, parenting, physical health, and mental health. It predicts avoiding many misfortunes, such as car accidents, jail, drug addiction, sexually transmitted diseases, divorce, and jury duty. It is one of the most sexually attractive traits in every culture studied, for both sexes. It is socially desired in friends, students, mentors, coworkers, bosses, employeees, housemates, and especially platoon mates. It remains ideologically controversial because its predictive power is so high, and its distribution across individuals is unequal.
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The other members of the Central Six are the Big Five personailty traits: openness, conscientiousness, agreeableness, stability, and extraversion. These are more recent discoveries, dating back from arount 1980, and they have revitalized the study of human personality. They clearly and efficiently map the main individual differences in human behavioral dispositions, and they are much more reliable and valid than other ways of describing human personality in psychology or marketing. Like general intelligence, they are genetically heritable, stable across life, and universal across cultures. Like intelligence, they are very salient when we choose social or sexual partners. They can be represented by the letters O, C, A, S, and E, and they can be reliably measured by several different personality questionnaires.
O is for openness to experience: curiosity, novelty seeking, broadmindedness, interest in culture, ideas, and aesthetics. ... People high on openness tend to seek complexity and novelty, readily accept changes and innovations, and prefer grand new visions to mundane, predictable ruts.
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C is for conscientiousness: self-control, willpower, reliability, consistency, dependability, trustworthiness, and the ability to delay gratification. Conscientious people pursue long-term goals. They fulfill their promises and commitments, resist impulses and bad habits, and feel embedded in a network of mutual social obligations. In Chinese terms, they tend to build strong guanxi - a strong, reliable social network. They like to make plans, keep everything organized, seek perfection, crave achievement, and prefer doing one focused task at a time. People low in conscientiousness tend to be more comfortable with spontaneity and chaos. They accept things, people, and achievement levels that are "good enough" rather than "optimal," and they shift more easily among ongoing tasks. Yet they also show lower levels of drive and ambition. Conscientiousness predicts regular attendance to school and work, completion of assignments on time, cooperativeness in professional relationships, and civic engagement. It predicts eating a healthy diet, exercising regularly, avoiding drug addiction, and staying healthy. Along with intelligence, it is one of the two traits most desired by employers. On the other hand, because conscientiousness predicts effective contraception use, it is strongly disfavoured by natural selection in the modern world. Extremely high conscientiousness shades over into obsessive-compulsive disorder and results in overwashed hands, whereas extremely low conscientiousness shades over into reckless impulsivity and results in long criminal records. Low conscientiousness is moderately related to one of the two main dimensions of mental illness: the "externalizing" dimension associated with childhood "conduct disorder" (deliquency), adult "antisocial disorder" (psychopathy), and "substance abuse" (alcoholism and drug addiction).
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A is for agreeableness: warmth, kindness, sympathy, empathy, trust, compliance, modesty, benevolence, peacefulness. Saints are very agreeable; psychopaths are very disagreeable. People high in agreeableness tend to seek harmony, adapt to others' needs, and keep their opinions to themselves when doing so avoids conflict. People low in agreeableness tend to seek glory or notoriety, persue their own needs, and express their opinions forcefully. Agreeableness is perceived not just as peronality trait, but as a moral trait. It corresponds to what most people would call "good" as opposed to "evil", "altruistic" as opposed to "selfish", "peaceful" as opposed to"aggressive". (Personality psychologists hate to sound judgmental about traits, so they try to avoid such moral terms.) Agreeable people often make much more pleasant long-term sexual partners, friend, relatives, in laws, co-workers, and babysitters, so we often value agreeableness in others. In game-theory terms, the agreeable make better reciprocators, and contribute more to public goods, because they value other people's well-being ("subjective utility"), not just their own. ... Disagreeable people, on the other hand, can often take social and sexual advantage of others, so there can be major evolutionary benefits to disagreeableness, especially for males. (This is why most wild animals are rather disagreeable, and why most humans, like other domesticated species, are much more agreeable.) People low in agreeableness can be cold, distant, aggressive, irritable, selfish, and arrogant; they lie, cheat, steal, rape, and kill more often. ... Low agreeableness, even more than low conscientiousness, is related to the externalizing dimension of mental illness (deliquency, psychopathy, alcoholism, drug addiction), and with various nasty behaviors that impose high costs on others (promiscuity, philandering, wife beating, child sexual abuse, reckless driving). Both agreeableness and conscientiousness tend to increase from early adulthood to middle adulthood, while externalizing decreases.
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S is for stability, especially emotional stability. Stability means adaptability, equanimity, maturity, stress resistance. People high in stability are resilient: usually optimistic, calm, at ease, and quick to rebound from setbacks. People low in stability are neurotic: anxious, worried, self-conscious, depressed, pessimistic, quick to anger, quick to cry, and slow to rebound from setbacks. Low stability coresponds with the "internalizing" dimension of mental illness that is associated with distress (major depression, dysthymia, generalized anxiety disorder) and fear (phobias and panic disorder). High stability correlates positively with general mental health and general happiness, including job satisfaction and marital satisfaction. In fact, in the developed world, emotional stability predicts overall life satisfaction more strongly than does income or any of the other Central Six traits.
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E is for Extraversion: how friendly, gregarious, talkative, funny, expressive, assertive, active, excitement seeking, and socially self-confident one is. Extraverts are social; introverts are loners. Almost all psychlogists from Carl Jung onward have agreed that extraversion is a key dimension of individual differences. Shyness arises as a combination of low extraversion and low stability. Extraverts also show higher "surgency" - higher levels of activity, power, dominance, and self-confidence. They show a lot of positive emotions, prefer working with and trusting others, enjoy leadership, and prefer being physically active. They go to parties more and drink more. They are more sexually adventurous and unconventional. Low extraversion is not just associated with shyness; its also associated with social passivity and low levels of social status seeking. People low in extraversion tend to suppress positive feelings, prefer working alone, prefer being physically passive, and are less trusting and less inclined to seek leadership roles. Since extraverts are more active and meet more people, they tend to have more friends and sexual partners.
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Spent. Geoffrey Miller; 2009