Dienstag, 29. Juli 2014

Intelligence moderates neural responses to monetary reward and punishment

Intelligence moderates neural responses to monetary reward and punishment
D.R. Hawes , C.G. DeYoung, J.R. Gray, A. Rustichini (2014)


Abstract

The relation between intelligence (IQ) and neural responses to monetary gains and losses were investigated in a simple decision task. In 94 healthy adults, typical responses of striatal BOLD signal after monetary reward and punishment were weaker for subjects with higher IQ. IQ-moderated differential responses to gains and losses were also found for regions in the medial prefrontal cortex, posterior cingulate cortex, and left inferior frontal cortex. These regions have previously been identified with the subjective utility of monetary outcomes. Analysis of subjects’ behavior revealed a correlation between IQ and the extent to which choices were related to experienced decision outcomes in preceding trials. Specifically, higher IQ predicted behavior to be more strongly correlated with an extended period of previously experienced decision outcomes, whereas lower IQ predicted behavior to be correlated exclusively to the most recent decision outcomes. We link these behavioral and imaging findings to a theoretical model capable of describing a role for intelligence during the evaluation of rewards generated by unknown probabilistic processes. Our results demonstrate neural differences in how people of different intelligence respond to experienced monetary rewards and punishments. Our theoretical discussion offers a functional description for how these individual differences may be linked to choice behavior. Together, our results and model support the hypothesis that observed correlations between intelligence and preferences may be rooted in the way decision outcomes are experienced ex post, rather than deriving exclusively from how choices are evaluated ex-ante.

Relationship between Smiling and Laughter in Humans (Homo sapiens): Testing the Power Asymmetry Hypothesis

Relationship between Smiling and Laughter in Humans (Homo sapiens): Testing the Power Asymmetry Hypothesis
Marc Mehu & Robin I.M. Dunbar (2008)


Abstract

The power asymmetry hypothesis claims that individuals should have distinct signals of appeasement/affiliation and play when status difference is high, whereas these signals should overlap in egalitarian interactions. Naturalistic observations were conducted on humans interacting in groups that differed in terms of age composition (and presumably social status). Three affiliative behaviours were recorded by focal sampling: spontaneous smiles, deliberate smiles and laughter. Interestingly, young men showed significantly higher proportions of deliberate smiles in comparison to laughter when interacting with people of a different age class than when interacting in same-age groups. The pattern of affiliative behaviours in women remained unaffected by the age composition of groups. This partly supports the power asymmetry hypothesis and suggests that in men, deliberate smiles could play a role in the regulation of hierarchical relationships.

A Winning Smile? Smile Intensity, Physical Dominance, and Fighter Performance

A Winning Smile? Smile Intensity, Physical Dominance, and Fighter Performance
Michael W. Kraus & Teh-Way David Chen (Jan 2013)


Abstract

The smile is perhaps the most widely studied facial expression of emotion, and in this article we examine its status as a sign of physical dominance. We reason, on the basis of prior research, that prior to a physical confrontation, smiles are a nonverbal sign of reduced hostility and aggression, and thereby unintentionally communicate reduced physical dominance. Two studies provide evidence in support of this prediction: Study 1 found that professional fighters who smiled more in a prefight photograph taken facing their opponent performed more poorly during the fight in relation to their less intensely smiling counterparts. In Study 2, untrained observers judged a fighter as less hostile and aggressive, and thereby less physically dominant when the fighters’ facial expression was manipulated to show a smiling expression in relation to the same fighter displaying a neutral expression. Discussion focused on the reasons why smiles are associated with decreased physical dominance.

Rushton - Suzuki Debate (February 1989)

https://www.youtube.com/watch?v=i9FGHtfnYWY&feature=youtu.be&t=8m19s

Montag, 28. Juli 2014

Cultural differences in indecisiveness: The role of naïve dialecticism

Cultural differences in indecisiveness: The role of naïve dialecticism
Andy H. Ng and Michaela Hynie (November 2014)
Personality and Individual Differences



Highlights

o East Asian Canadians (EAC) are more indecisive than European Canadians (EC).

o East Asian Canadians (EAC) are more indecisive than South Asian Canadians (SAC).

o EAC (vs. EC and SAC) exhibit lower need for cognition (NFC).

o EAC (vs. EC and SAC) exhibit higher naïve dialecticism (ND).

o NFC and ND mediate the relationship between culture and indecisiveness.



Abstract

East Asians exhibit naïve dialecticism, a set of worldviews that tolerates contradictions. As influenced by naïve dialecticism, East Asians are more likely to hold and less likely to change ambivalent attitudes, compared with European North Americans. If East Asians have a heightened tendency to see both positive and negative aspects of an object or issue, but a lesser inclination to resolve these inconsistencies, East Asians (vs. European North Americans) may experience more difficulty in committing to an action, and thus be more indecisive. Consistent with this hypothesis, we found that East Asian Canadians scored higher on a measure of chronic indecisiveness than did European Canadians and South Asian Canadians, and that naïve dialecticism and need for cognition mediated the relationship between culture and indecisiveness. These results add to the extant literature on indecisiveness, demonstrating cultural variations in indecisiveness and an underlying cultural factor that is responsible for these cultural differences.

Human Conversational Behavior

Human Conversational Behavior
R.I.M. Dunbar, A. Marriott, N.D.C. Duncan (1997)


Abstract

Observational studies of human conversations in relaxed social settings suggest that these consist predominantly of exchanges of social information (mostly concerning personal relationships and experiences). Most of these exchanges involve information about the speaker or third parties, and very few involve critical comments or the soliciting or giving of advice. Although a policing function may still be important (e.g., for controlling social cheats), it seems that this does not often involve overt criticism of other individuals' behavior. The few significant differences between the sexes in the proportion of conversation time devoted to particular topics are interpreted as reflecting females' concerns with networking and males' concerns with self-display in what amount to a conventional mating lek.

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>Comparisons within and between the three samples suggest that a number of important sex differences exist. One is a tendency for males to devote more conversation time to intellectual or work-related topics. A second is for this pattern to become exaggerated when females are present. A third is for male conversations to change more dramatically with age than those of females, ...<

Sonntag, 27. Juli 2014

The social role of touch in humans and primates: Behavioural function and neurobiological mechanisms

The social role of touch in humans and primates: Behavioural function and neurobiological mechanisms
R.I.M. Dunbar (2010)


Abstract

Grooming is a widespread activity throughout the animal kingdom, but in primates (including humans) social grooming, or allo-grooming (the grooming of others), plays a particularly important role in social bonding which, in turn, has a major impact on an individual’s lifetime reproductive fitness. New evidence from comparative brain analyses suggests that primates have social relationships of a qualitatively different kind to those found in other animal species, and I suggest that, in primates, social grooming has acquired a new function of supporting these. I review the evidence for a neuropeptide basis for social bonding, and draw attention to the fact that the neuroendrocrine pathways involved are quite unresolved. Despite recent claims for the central importance of oxytocin, there is equally good, but invariably ignored, evidence for a role for endorphins. I suggest that these two neuropeptide families may play different roles in the processes of social bonding in primates and non-primates, and that more experimental work will be needed to tease them apart.

Samstag, 26. Juli 2014

Examining the Possible Functions of Kissing in Romantic Relationships

Examining the Possible Functions of Kissing in Romantic Relationships
Rafael Wlodarski & Robin I. M. Dunbar (2013)


Abstract

Recent research suggests that romantic kissing may be utilized in human sexual relationships to evaluate aspects of a  potential mate’s suitability, to mediate feelings of attachment between pair-bonded individuals, or to facilitate arousal and initiate sexual relations. This study explored these potential functions of romantic kissing by examining attitudes towards the importance of kissing in the context of various human mating situations. The study involved an international online questionnaire, which was completed by 308 male and 594 female participants aged 18–63 years. Support was found for the hypothesis that kissing serves a useful mate-assessment function: women, high mate-value participants, and participants high in sociosexual orientation placed greater importance on kissing in romantic relationships and stated that an initial kiss was more likely to affect their attraction to a potential mate than did men, low-mate value participants or low sociosexual orientation participants. Kissing also seemed to be utilized in the mediation of pair-bond attachments: kissing was seen to be more important at established stages of relationships by low sociosexual participants, kissing was generally seen as more important in long-term relationship contexts (but particularly so by women), and kissing frequency was found to be related to relationship satisfaction. The findings of this research showed very little evidence to support the hypothesis that the primary function of kissing is to elevate levels of arousal.

Cognitive adaptations of social bonding in birds

Cognitive adaptations of social bonding in birds
N. J. Emery, A. M. Seed, A. M. P. von Bayern and N. S. Clayton (2007)
http://rstb.royalsocietypublishing.org/content/362/1480/489.full



Abstract

The ‘social intelligence hypothesis’ was originally conceived to explain how primates may have evolved their superior intellect and large brains when compared with other animals. Although some birds such as corvids may be intellectually comparable to apes, the same relationship between sociality and brain size seen in primates has not been found for birds, possibly suggesting a role for other non-social factors. But bird sociality is different from primate sociality. Most monkeys and apes form stable groups, whereas most birds are monogamous, and only form large flocks outside of the breeding season. Some birds form lifelong pair bonds and these species tend to have the largest brains relative to body size. Some of these species are known for their intellectual abilities (e.g. corvids and parrots), while others are not (e.g. geese and albatrosses). Although socio-ecological factors may explain some of the differences in brain size and intelligence between corvids/parrots and geese/albatrosses, we predict that the type and quality of the bonded relationship is also critical. Indeed, we present empirical evidence that rook and jackdaw partnerships resemble primate and dolphin alliances. Although social interactions within a pair may seem simple on the surface, we argue that cognition may play an important role in the maintenance of long-term relationships, something we name as ‘relationship intelligence’.

Freitag, 25. Juli 2014

The Decline of the ‘WASP’ in Canada and the United States

The Decline of the ‘WASP’ in Canada and the United States
Eric P. Kaufmann (2004)

Rumination and dysphoria: The buffering role of adaptive forms of humor

Rumination and dysphoria: The buffering role of adaptive forms of humor
M. L. Olson, D. S. Hugelshofer, P. Kwon, R. C. Ref
Personality and Individual Differences 39 (2005)


Abstract

The current study examines the effects of rumination and humor on individuals' dysphoria level. Measures of humor (affiliative and self-enhancing), rumination, and depressive symptoms were completed by 303 undergraduate students. Consistent with our hypothesis, both affiliative humor and rumination independently accounted for variance in dysphoria levels. In addition, self-enhancing humor and rumination were independently associated with dysphoria. Moreover, significant interactions between affiliative humor and rumination, and self-enhancing humor and rumination, on dysphoria also emerged. Results indicated that among individuals with high rumination, those with high affiliative and/or self-enhancing humor had significantly lower levels of dysphoria than individuals with low affiliative and/or self-enhancing humor. The combination of low affiliative and/or self-enhancing humor and high rumination led to substantially higher levels of dysphoria than any other combination. Implications for psychotherapy and research in this area are discussed.

Montag, 21. Juli 2014

Solving the puzzle of why Finns have the highest IQ, but one of the lowest number of Nobel prizes in Europe

Solving the puzzle of why Finns have the highest IQ, but one of the lowest number of Nobel prizes in Europe
Edward Dutton, Jan te Nijenhuis, Eka Roivainen
Intelligence (Sept - Oct 2014)


Highlights

Finland does very well in PISA, but has very few Nobel Prize winners.
Finns have the highest IQ in Europe but the smallest SD.
Finns have high Conscientiousness and Agreeableness.
This explains why they do well in education, but not in measures of significant creative achievement.


Abstract

Finland has been noted to perform consistently very well in the international PISA assessments for many years, but it also has a relatively low per capita number of Nobel Prize winners. We draw upon a large body of proxy data and direct evidence, including the first ever use of RTs to calculate the Finnish IQ and the first ever use of the WAIS IV and PISA scores in the same capacity. Based on these data, we hypothesize that Finns perform so consistently well in PISA because they have a higher IQ overall than other European countries and exhibit a specialized slow life history strategy characterized by high Agreeableness and Conscientiousness, and low Psychoticism and Extraversion. Most of these traits predict educational success but all would suppress genius and creativity amongst this population. We connect the present distribution of phenotypic traits amongst the Finnish population with evolutionary change starting in the Pleistocene, accelerating in the Holocene, and continuing into the present day. We argue that this profile explains why Finns are relatively poorly represented in terms of science Nobel laureates.

Montag, 14. Juli 2014

Sex differences in the implications of partner physical attractiveness for the trajectory of marital satisfaction.

Sex differences in the implications of partner physical attractiveness for the trajectory of marital satisfaction.
A L Meltzer, J K McNulty, G L Jackson, B R Karney (Mar 2014)


Abstract

Do men value physical attractiveness in a mate more than women? Scientists in numerous disciplines believe that they do, but recent research using speed-dating paradigms suggests that males and females are equally influenced by physical attractiveness when choosing potential mates. Nevertheless, the premise of the current work is that sex differences in the importance of physical attractiveness are most likely to emerge in research on long-term relationships. Accordingly, the current work drew from 4 independent, longitudinal studies to examine sex differences in the implications of partner physical attractiveness for trajectories of marital satisfaction. In all 4 studies, both partners’ physical attractiveness was objectively rated at baseline, and both partners reported their marital satisfaction up to 8 times over the first 4 years of marriage. Whereas husbands were more satisfied at the beginning of the marriage and remained more satisfied over the next 4 years to the extent that they had an attractive wife, wives were no more or less satisfied initially or over the next 4 years to the extent that they had an attractive husband. Most importantly, a direct test indicated that partner physical attractiveness played a larger role in predicting husbands’ satisfaction than predicting wives’ satisfaction. These findings strengthen support for the idea that sex differences in self-reported preferences for physical attractiveness do have implications for long-term relationship outcomes.

Fitness consequences of spousal relatedness in 46 small-scale societies

Fitness consequences of spousal relatedness in 46 small-scale societies
Drew H. Bailey, Kim R. Hill, and Robert S. Walker (April 2014)
biology letters


Abstract

Social norms that regulate reproductive and marital decisions generate impressive cross-cultural variation in the prevalence of kin marriages. In some societies, marriages among kin are the norm and this inbreeding creates intensive kinship networks concentrated within communities. In others, especially forager societies, most marriages are between more genealogically and geographically distant individuals, which generates a larger number of kin and affines of lesser relatedness in more extensive kinship networks spread out over multiple communities. Here, we investigate the fitness consequence of kin marriages across a sample of 46 small-scale societies (12 439 marriages). Results show that some non-forager societies (including horticulturalists, agriculturalists and pastoralists), but not foragers, have intensive kinship societies where fitness outcomes (measured as the number of surviving children in genealogies) peak at commonly high levels of spousal relatedness. By contrast, the extensive kinship systems of foragers have worse fitness outcomes at high levels of spousal relatedness. Overall, societies with greater levels of inbreeding showed a more positive relationship between fitness and spousal relatedness.