The Dopamine D4 Receptor (DRD4) Exon 3 VNTR Contributes to Adaptive Personality Differences in an Italian Small Island Population

Conceptual and methodological issues in the study of the personality-and-culture relationship

Culture-and-personality studies were central to social science in the early 20th century and have recently been revived (as personality-and-culture studies) by trait and cross-cultural psychologists. In this article we comment on conceptual issues, including the nature of traits and the nature of the personality-and-culture relationship, and we describe methodological challenges in understanding associations between features of culture and aspects of personality. We give an overview of research hypothesizing the shaping of personality traits by culture, reviewing studies of indigenous traits, acculturation and sojourner effects, birth cohorts, social role changes, and ideological interventions. We also consider the possibility that aggregate traits affect culture, through psychological means and gene flow. In all these cases we highlight alternative explanations and the need for designs and analyses that strengthen the interpretation of observations. We offer a set of testable hypotheses based on the premises that personality is adequately described by Five-Factor Theory, and that observed differences in aggregate personality traits across cultures are veridical. It is clear that culture has dramatic effects on the thoughts, feelings, and behaviors from which we infer traits, but it is not yet clear whether, how, and in what degree culture shapes traits themselves.

How to behave when marooned: the behavioural component of the island syndrome remains underexplored

Animals on islands typically depart from their mainland relatives in assorted aspects of their biology. Because they seem to occur in concert, and to some extent evolve convergently in disparate taxa, these changes are referred to as the 'island syndrome'. While morphological, physiological and life-history components of the island syndrome have received considerable attention, much less is known about how insularity affects behaviour. In this paper, we argue why changes in personality traits and cognitive abilities can be expected to form part of the island syndrome. We provide an overview of studies that have compared personality traits and cognitive abilities between island and mainland populations, or among islands. Overall, the pickings are remarkably slim. There is evidence that animals on islands tend to be bolder than on the mainland, but effects on other personality traits go either way. The evidence for effects of insularity on cognitive abilities or style is highly circumstantial and very mixed. Finally, we consider the ecological drivers that may induce such changes, and the mechanisms through which they might occur. We conclude that our knowledge of the behavioural and cognitive responses to island environments remains limited, and we encourage behavioural biologists to make more use of these 'natural laboratories for evolution'.

Using a Systems-Based Risk Score Approach to Examine Genetic Predisposition to Novelty Seeking

Abstract. Previous research is mixed regarding the relation between dopamine and Novelty Seeking. The goals of the current study were to support the hypotheses that Novelty Seeking is associated with dopamine genes and that modeling genetic risk score increases the utility of genetic information in hypothesis-driven research. The results showed that higher hypodopaminergic genetic risk score positively predicted higher Novelty Seeking score, F(1, 115) = 5.76, p < .01, R2 = 0.06. The findings support study hypotheses and, in combination with previous studies, show the utility of empirically validated system-based risk scores as a means of modeling genetic predisposition in neurobiological systems. This approach provides a mechanism for incorporating genetic predisposition into theory-driven multivariate etiological models of psychological constructs such as personality and mental illness.

Personality traits across cultures

Current questions in the study of personality traits across cultures include (a) the universality versus cultural uniqueness of trait structure, (b) cultural differences in trait levels, (c) the consistency and validity of traits and their measures across cultures, and (d) the evolutionary, ecological, and cultural contexts of personality. Although the Five Factor Model (FFM) of personality continues to find cross-cultural support, new research suggests that the model may be difficult to replicate in less educated or preliterate groups and that indigenous social-relational concepts may be distinguishable from the FFM in some cultures. In lexical studies, two or three broad dimensions may replicate better across cultures than alternative models. Substantial evidence suggests that mean trait profiles of cultures may be reasonably accurate. Nonetheless, research on response styles and measurement invariance raises questions about cross-cultural trait comparisons. Findings regarding cultural differences in trait-related consistency and validity are mixed. Researchers are offering innovative theory and research on the evolutionary, ecological, and cultural contexts of personality.