Mittwoch, 31. Juli 2013

Religious belief and intelligence: Worldwide evidence

Religious belief and intelligence: Worldwide evidence
Francisco Cribari-Neto and Tatiene C Souza; Sebtember-October 2013
Intelligence


Abstract

Is there a positive impact of intelligence on religious disbelief after we account for the fact that both average intelligence and religious disbelief tend to be higher in more developed countries? We carry out four beta regression analyses and conclude that the answer is yes. We also compute impact curves that show how the effect of intelligence on atheism changes with average intelligence quotients. The impact is stronger at lower intelligence levels, peaks somewhere between 100 and 110, and then weakens. Bootstrap standard errors for our point estimates and bootstrap confidence intervals are also computed.

MOST intelligent people are accurate and SOME fast people are intelligent.

MOST intelligent people are accurate and SOME fast people are intelligent. Intelligence, working memory, and semantic processing of quantifiers from a computational perspective
Marcin Zajenkowski and Jakub Szymanik; July-September 2013
Intelligence


Abstract

The paper explores the relationship between intelligence and the semantic processing of natural language quantifiers. The first study revealed that intelligence is positively associated  with the subjects' performance when solving a picture verification task with one of the four types of sentences: Aristotelian (e.g. ‘All cars are red’), parity (e.g. ‘An even number of cars are red’), numerical (e.g. ‘More than five cars are red’), and proportional (‘More than half of the cars are red’). The strongest relationship was observed between the cognitive ability and the accuracy of proportional sentences, in accordance with the computational theory which predicts the highest engagement of working memory (WM) within the group of proportional  quantifiers. Moreover, individuals with higher intelligence reacted faster, but this was  observed only in case of quantifiers with low complexity. Exploring further, in the second study we found that WM and intelligence were both significant predictors of subjects' score on proportional sentences. In the third study, we examined the relationships between quantifiers, intelligence, short-term memory (STM), and executive control function. STM was correlated with all types of quantifiers that need counting and keeping track of elements (parity, numerical, and proportional). Only proportional quantifiers were associated with cognitive control. The obtained results are discussed within the computational paradigm of language processing.

The general factor of personality and general intelligence: Evidence for substantial association

The general factor of personality and general intelligence: Evidence for substantial association
Curtis S Dunkel; September-October 2013
Intelligence


Abstract

Despite theoretical assertions derived from life history theory, research on the relationship between the general factor of personality and general intelligence has shown that there is little overlap between the two higher-order constructs. It is argued that the association between these general factors is largely attenuated by measurement error in assessing the general factor of personality. A substantial association between the general factors at multiple points in time was found when the general factor of personality was derived from rater Q-sorts. The results have important implications for the study of individual differences.

Attractive women want it all: Good genes, economic investment, parenting proclivities, and emotional commitment.

Attractive women want it all: Good genes, economic investment, parenting proclivities, and emotional commitment.
David Buss, Todd Schackelford; 2008


Abstract

The current research tests the hypothesis that women have an evolved mate value calibration adaptation that functions to raise or lower their standards in a long-term mate according to their own mate value. A woman’s physical attractiveness is a cardinal component of women’s mate value. We correlated observer-assessed physical attractiveness (face, body, and overall) with expressed preferences for four clusters of mate characteristics (N = 214): (1) hypothesized good-gene indicators (e.g., masculinity, sexiness); (2) hypothesized good investment indicators (e.g., potential income); (3) good parenting indicators (e.g., desire for home and children), and (4) good partner indicators  (e.g., being a loving partner). Results supported the hypothesis that high mate value women, as indexed by observer-judged physical attractiveness, expressed elevated standards for all four clusters of mate characteristics. Discussion focuses on potential design features of the hypothesized mate-value calibration adaptation, and suggests an important modification of the trade-off model of women’s mating. A minority of women—notably those low in mate value who are able to escape male mate guarding and the  manifold costs of an exposed infidelity—will pursue a mixed mating strategy, obtaining  investment from one man and good genes from an extra-pair copulation partner (as the trade-off model predicts). Since the vast majority of women secure genes and direct benefits from the same man, however, most women will attempt to secure the bestcombination of all desired qualities from the same man.

[Christian von "Alles Evolution" verfasste zu jenem Artikel ein sehr lesenswertes Kommentar: http://allesevolution.wordpress.com/2013/08/11/was-wollen-schone-frauen-bei-einem-partner/]

Social Network Changes and Life Events Across the Life Span: A Meta-Analysis

Social Network Changes and Life Events Across the Life Span: A Meta-Analysis
Cornelia Wrzus et al.; 2013


Abstract

For researchers and practitioners interested in social relationships, the question remains as to how large social networks typically are, and how their size and composition change across adulthood. On the basis of predictions of socioemotional selectivity theory and social convoy theory, we conducted a meta-analysis on age-related social network changes and the effects of life events on social networks using 277 studies with 177,635 participants from adolescence to old age. Cross-sectional as well as longitudinal studies consistently showed that (a) the global social network increased up until young adulthood and then decreased steadily, (b) both the personal network and the friendship network decreased throughout adulthood, (c) the family network was stable in size from adolescence to old age, and (d) other networks with coworkers or neighbors were important only in specific age ranges. Studies focusing on life events that occur at specific ages, such as transition to parenthood, job entry, or widowhood, demonstrated network changes similar to such age-related network changes. Moderator analyses detected that the type of network assessment affected the reported size of global, personal, and family networks. Period effects on network sizes occurred for personal and friendship networks, which have decreased in size over the last 35 years. Together the findings are consistent with the view that a portion of normative, age-related social network changes are due to normative, age-related life events. We discuss how these patterns of normative social network development inform research in social, evolutionary, cultural, and personality psychology.

You Can't Teach Speed: Sprinters Falsify the Deliberate Practice Model of Expertise

You Can't Teach Speed: Sprinters Falsify the Deliberate Practice Model of Expertise
Michael P Lombardo and Robert O Deaner; 2013
http://papers.ssrn.com/sol3/papers.cfm?abstract_id=2277977 (full version of the paper)


Abstract

Most scientists agree that expertise requires both innate talent and proper training. Nevertheless, the highly influential deliberate practice model (DPM) of expertise holds that either talent does not exist, or that its contribution to performance differences is negligible. It predicts that initial performance will be unrelated to achieving expertise and that a long period of deliberate practice — at least 10 years or 10,000 hours — is necessary and sufficient for achieving expertise. We tested these predictions in the domain of sprinting. Study 1 reviewed the biographies of 15 Olympic sprint champions. Study 2 reviewed the biographies of the 20 fastest male sprinters in U.S. history. In all documented cases, sprinters were exceptional prior to or coincident with their initiation of formal training. Furthermore, most reached world class status rapidly (Study 1 median = 3 years; Study 2 median = 7.5). Study 3 surveyed U.S. national collegiate championships qualifiers in sprints and throws. Sprinters recalled being faster as youths than did throwers, whereas throwers recalled greater strength and overhand throwing ability. Sprinters’ best performances in their first season of high school, generally the onset of formal training, were consistently faster than 95-99% of their peers. Collectively, these results falsify the DPM for sprinting. Because speed is foundational for many sports, they challenge the DPM generally.

Dienstag, 30. Juli 2013

Personality and Unrestricted Sexual Behavior: Correlations of Sociosexuality in Caucasian and Asian College Students

Personality and Unrestricted Sexual Behavior: Correlations of Sociosexuality in Caucasian and Asian College Students
Tiffany M Wright, Steven P Reise; June 1997
Journal of Research in Personality


Abstract

The goal of this study was to explore if and how personality characteristics are associated with sociosexuality (i.e., individual differences in the willingness to engage in sex outside the context of a committed relationship). Toward this end, we used correlation, multiple regression, and path analysis to examine the associations of sociosexuality with: (1) the normal-range personality traits of the five-factor model, (2) a sexual attitude\affect dimension called erotophobia-erotophilia, and (3) ego development. The sample consisted of 350 Asian and Caucasian college students. Our final path model indicated that, regardless of ethnicity, extroversion, low agreeableness, and erotophilia were direct predictors of unrestricted sociosexuality. Furthermore, openness was an indirect predictor of sociosexuality through its association with erotophilia. However, our final path model also included ethnic differences. Specifically, in the Caucasian sample low agreeableness and openness were significant predictors of erotophilia, but in the Asian sample low neuroticism and openness combined to predict erotophilia. Finally, an interaction was observed between ethnicity and ego development in predicting unrestricted sociosexuality. For our Caucasian sample, increases in ego development were negatively correlated with unrestricted sociosexuality, while for Asians, increasing levels of ego development were not associated with sociosexuality. In other words, as ego development increases, Caucasians become more like Asians in that they are more sexually constrained or restricted. In the conclusion, we offer explanations of the results and discuss findings in terms of several theories of human sexual behavior.

[Speculative thoughts about these findings: A very interesting finding. Historically, East Asians and Caucasians had roughly the same intelligence level (especially if you consider the dysgenic fertility patterns of European populations over the last 150 years), but maybe European populations, especially northwest European populations were evolutionarily more selected for a "free will", for "ego strength" and for moral idealistic beliefs (and I think these are the causes for European creativity).  So to say (healthy) ego development causes sexual restricted behavior in Caucasians, but not in Asians, because in the "Caucasian mind" the self or the ego plays a more important part than in the "Asian mind" and sexual restricted behavior of Asians is mainly caused by other mechanisms.]

The costs and benefits of flexibility as an expression of behavioural plasticity: a primate perspective

The costs and benefits of flexibility as an expression of behavioural plasticity: a primate perspective
Carel P van Schaik, May 2013
Phil Trans R Soc B


Abstract

Traditional neo-Darwinism ascribes geographical variation in morphology or in behaviour to varying selection on local genotypes. However, mobile and long-lived organisms cannot achieve local adaptation this way, leading to a renewed interest in plasticity. I examined geographical variation in orang-utan subsistence and social behaviour, and found this to be largely owing to behavioural plasticity, here called flexibility, both in the form of flexible individual decisions and of socially transmitted (cultural) innovations. Although comparison with other species is difficult, the extent of such flexibility is almost certainly limited by brain size. It is shown that brains can only increase relative to body size where the cognitive benefits they produce are reliably translated into improved survival rate. This means that organisms that are very small, face many predators, live in highly seasonal environments, or lack opportunities for social learning cannot evolve greater flexibility, and must achieve local adaptation through selection on specific genotypes. On the other hand, as body and brain size increase, local adaptation is increasingly achieved through selection on plasticity. The species involved are also generally those that most need it, being more mobile and longer-lived. Although high plasticity buffers against environmental change, the most flexible organisms face a clear limit because they respond slowly to selection. Thus, paradoxically, the largest-brained animals may actually be vulnerable to the more drastic forms of environmental change, such as those induced by human actions.

[In particular, humans were selected for behavioral plasticity; for big brains, high intelligence and a "free will".]




Evolution of Monogamy, Paternal Investment, and Female Life History in Peromyscus

Evolution of Monogamy, Paternal Investment, and Female Life History in Peromyscus
Eldin Jasarevic, Drew H Bailey et al.; 2013


Abstract

The timing of reproductive development and associated trade-offs in quantity versus quality of offspring produced across the life span are well documented in a wide range of species. The relation of these aspects of maternal life history to monogamy and paternal investment in offspring is not well studied in mammals, due in part to the rarity of the latter. By using five large, captive-bred populations of Peromyscus species that range from promiscuous mating with little paternal investment (P. maniculatus bairdii) to social and genetic monogamy with substantial paternal investment (P. californicus insignis), we modeled the interaction between monogamy and female life history. Monogamy and high paternal investment were associated with smaller litter size, delayed maternal reproduction that extended over a longer reproductive life span, and larger, higher quality offspring. The results suggest monogamy and paternal investment can alter the evolution of female life-history trajectories in mammals.

‘Slow’ reproductive strategy: A negative predictor of depressive symptomatology

‘Slow’ reproductive strategy: A negative predictor of depressive symptomatology
Cezar Giosan; 2013


Abstract

The present study examined the associations between a high-K (slow) life history strategy and depressive symptomatology. The participants were a sample of 494 male utility workers who underwent psychological evaluations. It was hypothesised that high-K will correlate negatively with, and will be a negative predictor of, depressive symptomatology. The results confirmed the predictions, showing that high-K accounts for 15% of the variance in depressive symptomatology after controlling for risk factors for depression such as demographics, prior traumatic experiences, past depression, and recent negative life events. Implications of the results are discussed.

Montag, 29. Juli 2013

A Neuropsychological Study of Personality: Trait Openness in Relation to Intelligence, Fluency, and Executive Functioning

A Neuropsychological Study of Personality: Trait Openness in Relation to Intelligence, Fluency, and Executive Functioning
David J Schretlen et al.; 2010
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2937090/


Abstract

Openness is a personality trait that has been linked to intelligence and divergent thinking. DeYoung, Peterson, and Higgins (2005) theorized that trait Openness depends on dopamine function, especially in the prefrontal cortex. We tested their theory in 335 healthy adults by hypothesizing that individual differences in Openness would correlate more strongly with performance on tests of executive function than on tests of intelligence and fluency. However, Openness correlated more strongly with verbal/crystallized intelligence (Gc; r=0.44) than with executive functioning (r=0.16) and fluency (r=0.24). Further, the partial correlation between Openness and Gc increased from r=0.26 among young adults to r=0.53 among elderly adults. These findings suggest that Openness is more closely associated with the acquisition of broad verbal intellectual skills and knowledge than with executive abilities localized to a specific brain region or neurotransmitter system.

Sonntag, 28. Juli 2013

Female Reproductive Success: Nurturance versus Status

>Unlike men, women cannot generally enhance their reproductive success by acquiring wealth or accumulating mates, and in some cases it appears that women undermine their reproductive success by acquiring political status. As primatologist Barbara Smuts has suggested, competition among females is at a low level because "the outcome of a single interaction rarely leads to large variations in reproductive success because female reproductive performance depends mainly on the ability to sustain investment in offspring over long periods of time." In contrast to men, then, women have increased their reproductive success by devoting the bulk of their energies to investment in children, through provision of milk and other forms of direct caretaking, rather than through acquisition of resources.
There is reason to believe that the closer connection of women to their infants is an evolved response, as a general tendency in an mammalian mother to be indifferent to be indifferent to separation from  her infant would have been highly disadvantageous. An intriguing line of evidence implying sex differences in the factors that activate parental feelings and behaviors are studies finding that among non-genetic parents, women's attachment may suffer more than men's. For example, stepfathers tend to have better relationships with their stepchildren than stepmothers do and are more likely to report parental feelings. Similarly, the relationship of adoptive mothers to their adoptive children seems to resemble the genetic mother-child relationship less than the relationship of adoptive fathers resembles the genetic father-child relationship. A study by psychologist Irwin Silverman and colleagues examined perception of parental solicitude among adults who had been raised either by birth parents or adoptive parents. Not surprisingly, birth children tended to perceive their mothers as the more solicitous parent. However, adoptees reported substantially less parental solicitude from their mothers than birth children did, but there was no such decline in solicitude between birth and adoptive fathers. Indeed, adoptive fathers tended to be rated higher in solicitude than adoptive mothers. These findings can plausibly be interpreted to mean that experience of carrying and giving birth to a child predisposes women toward later nurturing feelings and behavior toward their children, while for fathers other factors trigger these feelings. Psychologist Geoffrey Miller has suggested that in our ancestral environment women commonly had children by successive males and that an evolved willingness to invest somewhat in stepchildren (although less than in their own biological offspring) may has been selected for as mating tactic.
Substantial reproductive tradeoffs for female competition and aggressiveness may limit the development of dominance in females. Among baboons, for example, high-ranking females obtain some clear reproductive benefits as a consequence of enhanced access to nutritional resources: they have higher infant survival, shorter interbirth intervals, and daughters who usually give birth at a younger age. Their lifetime reproductive success, however, may not substantially exceed that of less-dominant females. Dominant females have greater miscarriage rates and may show signs of reduced fertility. Thus, the same causal factors that lead to high dominance may also carry reproductive costs that have acted as a constraint on selection for competitiveness among females. That common factor is likely to be testosterone.
The same effect may occur in humans. It is often reported that female executives have fewer children than male executives and fewer than the average woman. A study of law school graduates found that 40 percent of women remained childless fifteen years after graduation. The usual implication of these findings is that women must choose between work and family and that these women chose work. There is another possible explanation, however. Women who succeed in business tend to be relatively high in testosterone, which can result in lower female fertility, whether because of ovulatory irregularities or reduced interest in having children. Thus, rather than the high-powered career being responsible for the high rate of childlessness, it may be that high testosterone levels be responsible for both.<

Kingsley R Browne; 2002
Biology at Work- Rethinking Sexual Equality

The intimacy / size trade-off

>Women's friendships have a different flavor to those of men both quantitatively and qualitatively. From childhood on, girls prefer to have one or two intimate friends while boys play in larger groups (Rose & Rudolph, 2006). This is not to say that boys never engage in two-person interactions. In one study, boys and  girls spent about equal amounts of time in dyadic interactions but for girls these exchanges occurred with a fewer range of people and were more extended in time. Boys moved from one partner to the next, spending less time with each of them (Beneson, Apostoleris, & Parnass, 1997). In a study of young people at summer camp, researchers examined network density: the proportion of a child's friends who were friends with each other (Parker & Seal, 1996). Boys and girls began with the same network density but by the end, boys' network densities were considerably larger than those of girls. Over time, boys' circles of friends expanded leading to greater interconnection while the girls' networks became increasingly restricted. Girls' friendships are more exclusive and more intense.
A key part of the intensity of female friendships is their intimacy. As one teenage girl put it "girls can talk to each other, boys keep things into themselves, they don't tell no one nothing" (Brown, 1998). For women intimacy means self-disclosure - confiding private details and experiences to another person. Self-disclosure can be broken down further, however, into descriptive self-disclosure (in which we share facts about our lives) and evaluative self-disclosure (in which we reveal the emotional impact that these experiences have had on us). Men's friendships seem to include a comparable degree of descriptive disclosure but less evaluative disclosure than women's (Cross & Madson, 1997). Men are especially reluctant to disclose negative emotional experiences such as depression, sadness, anxiety, and fear, whereas discussion of these vulnerabilities is the mainstay of close female friendships. This sex difference does not seem to be linked to different motivations - men express just as much interest and desire to have close relationships as women do. But studies of their actual patterns of self-disclosure suggest that they reserve it for women rather than sharing it with men (Dindia & Allen, 1992). In men's friendships, intimacy revolves around experiences that are relevant to their shared interests. They discuss public-domain issues that they have in common such as sport, business, and government. Men believe that these common interests and activities are the most important factor in their friendships. Women are more likely to talk about personal topics such as feelings, relationships, and problems (Bischoping, 1993; Caldwell & Peplau, 1982).
When things go wrong, girls and women turn to their friends for emotional empathy and advice. Women provide a sympathetic ear and are more focused on supportive listening than on problem solving. Men react to stressors by distracting themselves or putting the problem out of their mind: " A problem shared is a problem doubled" seems to typify their view. To men, unburdening to a friend not only advertises an inability to solve their own problems but entails divulging errors of judgment - weaknesses that gave rise to the problem in the first place. But women's reliance on female friends carries its own hazards. When faced with a problem, women find it hard to resist co-rumination; they re-run and re-analyze the stressful incident from every possible angle, entertaining different solutions and different possible futures. The tendency to dwell on negative incidents contributes to women's higher rates of depression (Hankin, Stone, & Wright, 2010; Rose, 2002).
...
Because time and energy are finite, all of us face a necessary trade-off between the size of our friendship group and the intensity of each friendship (Geary, 2010). But women and men have solved it in different ways. Women have opted for intensity and men for size. When asked to make direct choice between their preference for a larger number of friends or a higher intimacy with each of them (defined as emotional support and willingness to help solve personal problems), men go for number significantly more than women (Vigil, 2007). Men report having more friends than women, while women invest more time in their fewer friendships; they spent longer than men talking to their best friends, specifically about personal feelings and relationships. Make no mistake: men need and value friends. The proccupation with dominance ... does not mean that men are social isolates (Baumeister & Sommer, 1997). Nor is there anything second-rate about male friendships: boys and men report just as much satisfaction with their relationships as women (Lempers & Clark-Lempers, 1993; Parker & Asher, 1993). But they reflect a different set of priorities.
...<

A mind of her own
Anne Campbell; 2013

Sonntag, 21. Juli 2013

Are there "his" and "hers" types of interdependence?

Are there "his" and "hers" types of interdependence? The implications of gender differences in collective versus relational interdependence for affect, behavior, and cognition.
Gabriel, Shira; Gardner, Wendi L.; Sep. 1999
Journal of Personality and Social Psychology


Abstract

In a recent review, S. E. Cross and L. Madson (1997) forwarded that many gender differences in social experience and behavior may be better understood through consideration of gender differences in independence and interdependence. In the current studies an expansion of the model to include both relational and collective aspects of interdependence was investigated (see R. F. Baumeister & K. L. Sommer, 1997). On the basis of the literature regarding gender differences in affect, behavior, and cognition, it was hypothesized that women would focus more on the relational aspects of interdependence, whereas men would focus more on the collective aspects of interdependence. Five studies in which gender differences in self-construals, emotional experience, selective memory, and behavioral intentions were examined supported the expansion of the model to include both relational and collective aspects of interdependence.

["When reflecting on or describing themselves (e.g., completing "I am ..."), women are more likely than men to view themselves in terms of close relationships with family members or friends, whereas men are more likely to view themselves as members of groups or teams." D.Geary]

Freitag, 19. Juli 2013

Sex Differences in Social Play

>Social Play is very common in mammals; in many species of bird; and in a few species of fish, reptile, and invertebrate (Burghardt, 2005). The most common form is play fighting, which typically involves chasing and rough and tumble components; the latter can include wrestling, muted biting, pouncing and jumping on partners, pushing, and so forth (Archer, 1992; Panksepp, Siviy, & Normansell, 1984; Powers, 2000; J.R. Walters, 1987). Play fighting typically involves pairs of evenly matched (e.g., in terms of size) individuals and increases in frequency from infancy to the juvenile years and then slowly declines, often merging into serious fighting by reproductive age. Play fighting includes many of the same components of intrasexual fighting or territorial defense but differs in enough ways to make a straightforward practice of fighting behaviors unlikely in most species (Pellis & Pellis, 2007). In fact, many of the basic behavioral components of species-species fighting are evident at birth, but their expression is often better controlled, more nuanced, and more varied for individuals that have engaged in play fighting. By enabling the development of better controlled and more flexible fighting skills, this form of play likely results in later social competitive advantage (Pellis & Pellis, 2007; P.K. Smith, 1982).
Unlike locomotor and object-oriented play, sex differences in play fighting are found in a wide range of species, with the form and intensity of this play closely tracking sex differences in the form and intensity of intrasexual competition and other agonistic behaviors in adulthood (Maestripieri & Ross, 2004; Power, 2000; P.K. Smith, 1982). Across species of marsupials (e.g., red kangaroos, Macropus rufus), pinnipeds (e.g., northern elephant seal, M. angustirostris), ungulates (S. ibex), rodents (Norway rat, Rattus norvegicus) and primates (e.g., chimpanzee, Pan troglodytes), Power found that males of polygynous species with intense physical male-male competition nearly always engaged in more play fighting during development than did conspecific females; these sex differences are not found in their monogamous cousins with less intense intrasexual competition (Aldis, 1975; P.K. Smith, 1982). Carnivores are the exception that seems to prove the rule. Intense competition over mates or food is the norm for males and females of most of these species, and both sexes tend to engage in play fighting during development. A notable exception among carnivores is the spotted hyena in which females compete fiercely with other females over food, are polyandrous, and are dominant over males (East, Burke, Wilhelm, Greig, & Hofer, 2003). In this species, females engage in more play fighting than males (J.M. Pederson et al., 1990).
Play parenting is one form of social play that is consistently more common in females than in males, although it can occur in both sexes (Nicolson, 1987; Pryce, 1993, 1995). When presented with an array of children's toys, G.M. Alexander and Hines (2002) found that female vervet monkeys (Cercopithecus aethiops sabaeus) carried and played with dolls much more than their brothers; their brothers engaged in more play with a ball and toy car. Hassett, Siebert, and Wallen (2008) found the same sex difference for rhesus macaques (Macaca mulatta). For primates in general, play parenting and general interest in infants is most frequently observed in young females that have not yet had their first offspring. For many of these species, play parenting (e.g., caring for siblings) is associated with higher survival rates of their first-born, and sometimes later born, offspring (Nicolson, 1987). Across five primate species it was found that first-born survival rates were two to more than 4 times higher for mothers with early experience with infant care obtained through play parenting than for mothers with no such experience (Pryce, 1993). Maternal behavior is also influenced by the hormonal changes that occur during pregnancy and the birthing process, such that a combination of play parenting and these hormones contribute to maternal skill in many primates (Pryce, 1995).<

David C. Geary; 2010
Male, Female - The Evolution of Human Sex Differences;

Donnerstag, 18. Juli 2013

Sex Differences in Same-Sex Friendship

Sex Differences in Same-Sex Friendship 
Mayta A Caldwell and Letitia Anne Peplau; 1982


Abstract

Two studies examined sex differences in the same-sex friendships of college men and women. In a questionnaire study, self-reports were obtained of number of friends and frequency of interaction, typical and preferred kinds of interactions with friends, and emotional intimacy. A role-play study provided more direct information about conversations between friends. Men and women did not differ in quantitative aspects of friendship such as number of friends or amount of time spent with friends, nor in the value placed on intimate friendships. However, clear sex differences were found in both studies in the nature of interactions with friends. Women showed emphasis on emotional sharing and talking; men emphasized activities and doing things together. Results are discussed in terms of life-cycle constraints on friendship, and the possibility of sex differences in standards for assessing intimacy in friendship is considered.

The Cultural Divide: Book Reading as a Signifier of Boundaries among Co-Cultures in Israeli Society

The Cultural Divide: Book Reading as a Signifier of Boundaries among Co-Cultures in Israeli Society
Adoni Hanna, Nosek Hillel;
Israel Studies Review; Summer 2013


Abstract

This article investigates the function of book reading in a society consisting of a multiplicity of ethno-cultural communities, asking whether book reading functions as a unifying factor within each ethno-cultural community or as a dividing factor and as a signifier of boundaries between them. It is based on multiyear survey data among representative samples of Israeli urban adults (1970, 1990, 2001-2002, 2007, and 2011), focus groups, and analysis of bestseller lists (2001, 2002). The article demonstrates that book reading functions as a signifier of boundaries within Israeli society, namely between ethno-cultural co-cultures of veteran Jewish Israelis, Jewish immigrants from the former Soviet Union, and Israeli Arabs. This supports Morley and Robins's claim that cultural consumption may be a divisive factor between the co-cultures within nation-states.

Freitag, 12. Juli 2013

The effects of intelligence and education on the development of dementia. A test of the brain reserve hypothesis

The effects of intelligence and education on the development of dementia. A test of the brain reserve hypothesis
B Schmand et al.; 1997


Abstract

Background. A number of recent epidemiological studies have shown that the prevalence and incidence of dementia are increased in population strata with low compared to high levels of education. This has been explained as a consequence of a greater ‘ brain reserve capacity ’ in people with a high level of education. Theoretically, however, brain reserve capacity is better reflected by intelligence than by level of education. Thus, the emergence of dementia will be better predicted by low pre-morbid intelligence than by low education.

Methods. This prediction was tested in a population based sample of elderly subjects (N l 2063 ; age range 65–84 ; Amsterdam Study of the Elderly) who were followed over 4 years. Dementia was diagnosed using the Geriatric Mental State examination (GMS). Pre-morbid intelligence was measured using the Dutch Adult Reading Test (DART), a short reading test which gives a good estimate of verbal intelligence, and is relatively insensitive to brain dysfunction. The effects of age, gender, occupational level, number of diseases affecting the central nervous system and family history of dementia or extreme forgetfulness were also examined.

Results. Logistic regression analysis showed that low DART-IQ predicted incident dementia better than low level of education. A high occupational level (having been in charge of subordinates) had a protective effect.

Conclusions. This result supports the brain reserve theory. It also indicates that low pre-morbid intelligence is an important risk factor for cognitive decline and dementia. Use of reading ability tests is to be preferred over years of education as estimator of pre-morbid cognitive level in (epidemiological) dementia research.

Intelligence and reading ability in grades 2–12

Intelligence and reading ability in grades 2–12
Ronald P Carver
Intelligence, October- December 1990


Abstract

It has been hypothesized that the relationship between reading ability and intelligence—as measured by the Raven Progressive Matrices test—is small and insignificant. It has also been hypothesized that this relationship is higher in the upper grades of school as compared to the lower grades. These two hypotheses were investigated by administering the Raven Progressive Matrices test and the National Reading Standards test to 486 students in Grades 2–12 of a small-town, rural school district. The correlations between these two tests for each of Grades 2–12 varied from about .40 to .60 with an average of about .50. There was no trend indicating that the correlation increased with each grade in school. Criteria have been developed for judging the effect size of correlations, and this .50 correlation would be considered as large. These data can be interpreted as indicating that general intelligence, as measured by the Raven test, has a strong and consistent relationship to reading ability.


[If alphabetism is the ability to vocalize written words, there are not many analphabets in the Western world. If alphabetism is the ability to understand written material, every human population contains quite a few analphabets.]

Donnerstag, 11. Juli 2013

Genes & Reading Ability

Nature, nurture, and expertise
Robert Plomin et al.; 2013
http://www.sciencedirect.com/science/article/pii/S0160289613000810


Abstract

Rather than investigating the extent to which training can improve performance under experimental conditions (‘what could be’), we ask about the origins of expertise as it exists in the world (‘what is’). We used the twin method to investigate the genetic and environmental origins of exceptional performance in reading, a skill that is a major focus of educational training in the early school years. Selecting reading experts as the top 5% from a sample of 10,000 12-year-old twins assessed on a battery of reading tests, three findings stand out. First, we found that genetic factors account for more than half of the difference in performance between expert and normal readers. Second, our results suggest that reading expertise is the quantitative extreme of the same genetic and environmental factors that affect reading performance for normal readers. Third, growing up in the same family and attending the same schools account for less than a fifth of the difference between expert and normal readers. We discuss implications and interpretations (‘what is inherited is DNA sequence variation’; ‘the abnormal is normal’). Finally, although there is no necessary relationship between ‘what is’ and ‘what could be’, the most far-reaching issues about the acquisition of expertise lie at the interface between them (‘the nature of nurture: from a passive model of imposed environments to an active model of shaped experience’).

Does Childhood Television Viewing Lead to Attention Problems in Adolescence?

Does Childhood Television Viewing Lead to Attention Problems in Adolescence? Results From a Prospective Longitudinal Study
Carl Eric Landhuis et al.; 2007
http://pediatrics.aappublications.org/content/120/3/532.long


Abstract

CONTEXT. There is controversy over whether childhood television viewing causes attention problems. The findings from cross-sectional and longitudinal studies have been mixed. To our knowledge, no longitudinal studies have assessed the impact of children's television viewing on attention problems in adolescence. The objective of this study was to assess this association.
DESIGN, PARTICIPANTS, AND SETTING. Study members were a general population birth cohort of 1037 participants (502 female) born in Dunedin, New Zealand, between April 1972 and March 1973. Parental estimates of children's television-viewing time were obtained at ages 5, 7, 9, and 11 years. Self-, parent-, and teacher-reported attention problems in adolescence were obtained at ages 13 and 15 years.
RESULTS. The mean of hours of television viewing during childhood was associated with symptoms of attention problems in adolescence. These associations remained significant after controlling for gender, attention problems in early childhood, cognitive ability at 5 years of age, and childhood socioeconomic status. This association was also independent of adolescent television viewing.
CONCLUSIONS. Childhood television viewing was associated with attention problems in adolescence, independent of early attention problems and other confounders. These results support the hypothesis that childhood television viewing may contribute to the development of attention problems and suggest that the effects may be long-lasting.

Mittwoch, 10. Juli 2013

TV-Konsum der Österreicher/innen erreichte 2012 bisherigen Höchstwert

Mit einer durchschnittlichen TV-Nutzungszeit von 169 Minuten pro Tag verbrachten die Österreicher/innen (ab 12 Jahren) im vergangenen Jahr mehr Zeit vor den Fernsehgeräten als je zuvor. Die Verweildauer – die Nutzungszeit der an einem Tag jeweils fernsehenden Bevölkerung – betrug dabei 261 Minuten pro Tag – ebenfalls ein historischer Höchstwert. Zugenommen hat zum dritten Mal in Folge auch die TV-Reichweite: 2012 erreichte das Medium Fernsehen täglich 4,6 Mio. Österreicher/innen, das entspricht einer Tagesreichweite von 64 %.


http://mediaresearch.orf.at/index2.htm?fernsehen/fernsehen_nutzungsverhalten.htm


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Werte für Deutschland:













(Zum Vergrößern auf das Bild klicken.)
http://www.ard-zdf-onlinestudie.de/index.php?id=353


[Was macht Herr Müller, wenn er zu viel Freizeit hat? Er sieht fern. 3 bzw. 4 Stunden tägliche Sehzeit (etwa ab dem 13. Lebensjahr) bedeuten schlicht, dass der Durchschnittsösterreicher bzw. der Durchschnittsdeutsche ungefähr einen Zeitraum von neun bzw. zwölf Jahren durchgehend vor dem Fernseher verbringt. Abzüglich der Schlafzeiten lässt sich dies etwa mit der Wachzeit von 13,5 bzw. 18 Lebensjahren gleichsetzen.]

Dienstag, 9. Juli 2013

Education and Verbal Ability over Time: Evidence from Three Multi-Time Sources

Education and Verbal Ability over Time: Evidence from Three Multi-Time Sources
N H Nie et al.; 2009
http://www.learningace.com/doc/1391311/129f7bd3448db86d19dba0cae2553072/education_and_verbal_ability


Abstract

During the 20th century there was an unprecedented expansion of the level in educational attainment in America. We use three separate measures to investigate whether there was a concurrent increase in verbal ability and skills. We look for changes in verbal ability in the general population as well as graduates of different levels of education. An additional investigation of the relationship between gender differences in educational attainment and gender differences in verbal ability follows. We find no evidence that the large increase in educational attainment resulted in an increase in any of the measures of verbal abilities and skills.

Career chances among different segments of the IQ continuum:


[Full size: click at the image]

Source:  Linda S Gottfredson; g, Jobs and Life

Montag, 8. Juli 2013

Creatures of the night: Chronotypes and the Dark Triad traits

Creatures of the night: Chronotypes and the Dark Triad traits
Peter K Jonason at al.; September 2013
Personality and Individual Differences


Abstract

In this study (N = 263) we provide a basic test of a niche-specialization hypothesis of the Dark Triad (i.e., narcissism, psychopathy, and Machiavellianism). We propose that in order to best enact a “cheater strategy” those high on the Dark Triad traits should have optimal cognitive performance and, thus, have a night-time chronotype. Such a disposition will take advantage of the low light, the limited monitoring, and the lessened cognitive processing of morning-type people. The Dark Triad composite was correlated with an eveningness disposition. This link worked through links with the “darker” aspects of the Dark Triad (i.e., Machiavellianism, secondary psychopathy, and exploitive narcissism); correlations that were invariant across the sexes. While we replicated sex differences in the Dark Triad, we failed to replicate sex differences in chronotype, suggesting eveningness may not be a sexually selected trait as some have argued but is a trait under natural selective pressures to enable effective exploitations of conspecifics by both sexes.







Montag, 1. Juli 2013

A negative Flynn effect in Finland, 1997–2009

A negative Flynn effect in Finland, 1997–2009
E Dutton & R Lynn
Intelligence, Article in Press,
Available Online 30 June 2013



Abstract

The average IQs of approximately 25,000 18–20 year old male military conscripts in Finland per year are reported for the years 1988 to 2009. The results showed increases in the scores on tests of Shapes, Number and Words over the years 1988 to 1997 averaging 4.0 IQ points a decade. From 1997 to 2009 there were declines in all three tests averaging 2.0 IQ points a decade.



"[There] were few non-European immigrants in Finland during the years 1997–2009. In 2012, 4.8% of the Finnish population were immigrants or had at least one immigrant parent (Statistics Finland, 2012) and the great majority of these were Russians and Estonians, whose average IQ is the approximately same as that of the Finns at around 100 (Lynn & Vanhanen, 2012). Those of non-European, including American, origin made up just 1.8% of the Finnish population in 2012 (Statistics Finland, 2012). Thus, the decline of IQs in Finland cannot be attributed to the arrival of significant numbers of immigrants who may have had lower average IQs than the indigenous population. The most probable reason for the declines in IQs that have now been recorded in a number of countries is the presence of dysgenic fertility..."

[In comparison to other European countries only few non-Europeans immigrated into Finland in the last decades. Therefore the negative changes of the Finnish national IQ-level seem to be mainly caused by dysgenic / IQ lowering fertility patterns of the Finnish population.]