关键词: 人格差异性, 进化心理学, 解释

Abstract: Personality, from an evolutionary perspective, represents a meta-category of the output of a suite of species-typical, relatively domain-specific, evolved psychological mechanisms designed in response to the social adaptive problems recurrently faced by our ancestors. This conceptualization of human personality provides for novel and valuable reinterpretations of several areas of personality psychology including personality consistency, individual differences in personality, sex differences and similarities, and contextual determinants of personality. The personality commonality has always been discussed in evolutionary psychology, but some researchers hold that the personality differences also need to be focused because commonality and differences are two inseparable sides of personality. The founder of the personality psychology, Allport has put forward common traits and personal traits for a very long time, underlying the dual nature of personality: the commonality and diversity. And he paid much attention on the difference between personal traits and personality diversity, on the basis of distinguishing personality traits into cardinal traits, central traits, secondary traits, while early evolutionary psychologists focus on common traits with their thoughts that is the major products or byproducts and personal traits is the accessory during the evolution process. However, more and more evidence from evolutionary psychology researches suggest that the diversity of personality is not the supplementary, but the necessity with reasonable background and rationality. Thus, theories to explain the diverse personality have come up. The evolutionary explanations to personality differences can be divided into three categories: Life-history Theory, Genetic Diversity Theory and Costly Signaling Theory. Life-history Theory considers that personality differences are the product of the evolution of different life and history strategies (strategy K and strategy R) resulted from different environments (stable and unstable). Genetic Diversity Theory explains the personality differences from the perspective of gene mutation and balancing selection. The former emphasizes on the “contending and confrontation” between mutant gene and natural selection, and the remaining mutant gene provides the basis of personality differences; the latter contains two aspects－Frequency-dependent Selection and Environmental Heterogeneity in Fitness Optima, whose commonality stresses the “harmony and friendship” between mutant gene and natural selection and whose difference is: Frequency-dependent Selection means that there are many existent and progenitive strategies in the same context and a variety of selection strategies will retain at last because their adaptive value will be overturned by the change of proportion of each strategy in the group; Environmental Heterogeneity in Fitness Optima is that the partial existent and progenitive strategies lie in each natural environment. In all, selection strategy, to some extent, can maintain the diversity. Costly Signaling Theory holds that everyone has the motivation to transfer the signal to the outside world, which can present one’s gender, age, health, fertility, social status and gene quality, but due to the different ranks of transferring signals resulted from the natural endowment or resources differences, which drives individual to choose different behavioral strategies. The research in the future needs to focus on three directions: (1) to reinforce the research on genetics; (2) to increase the evidence from physiology research, especially the brain science; (3) to innovate the research methods and to overcome the three logic flaws of the current research paradigms.

Key words: personality differences, evolutionary psychology, explanation