Can Evolutionary Psychology Explain Individual Differences in Personality?
“Yes, we are all individuals!”
Can evolutionary psychology explain individual differences in personality?
It is now a “rule” that “all human behavioural traits are heritable” (Turkeimer, 2000. cited in Pinker 2002). Pinker says that when psychologist Eric Turkheimer made this bold claim in 2000, he was encapsulating over 40 years of studies that overwhelmingly and robustly support this view, and only slightly exaggerating (Pinker 2002). Estimates of the mean heritability for the fundamental traits in the most popular model of human personality (the Five Factor Model) are estimated to be between 42% (for agreeableness) and 57% (for openness to experience) (Bouchard & McGue, 2003). The obvious questions arise from these important and robust findings – is natural selection involved in moulding personality and, if so, how.
This paper will discuss three main models of evolutionary selection relating to personality that have been proposed to answer these questions. Most of the work is speculative and observational generalities rather than experimentally derived findings are generally used, so any comparison of the theories is mostly based on the internal logic of the arguments and their concordance with current understanding of more fundamental genetic research. For the purpose of this paper, the terms behavioural traits and personality traits, although not identical, are used interchangeably.
When considering a role for natural selection in developing personality traits the problem that arises is how to account for the wide variation in expression of these traits, where only the most extreme presentations appear to be disadvantageous and thus rare (Buss, 2008; Nettle, 2006; Penke, Denissen & Miller, 2007). For example, the trait of openness to experience has a very wide range of expression, from astronauts to the contemplative monk and everything in between.
Attempts to understand the existence of such large individual variation within personality has
Can evolutionary psychology explain individual differences in personality?
It is now a “rule” that “all human behavioural traits are heritable” (Turkeimer, 2000. cited in Pinker 2002). Pinker says that when psychologist Eric Turkheimer made this bold claim in 2000, he was encapsulating over 40 years of studies that overwhelmingly and robustly support this view, and only slightly exaggerating (Pinker 2002). Estimates of the mean heritability for the fundamental traits in the most popular model of human personality (the Five Factor Model) are estimated to be between 42% (for agreeableness) and 57% (for openness to experience) (Bouchard & McGue, 2003). The obvious questions arise from these important and robust findings – is natural selection involved in moulding personality and, if so, how.
This paper will discuss three main models of evolutionary selection relating to personality that have been proposed to answer these questions. Most of the work is speculative and observational generalities rather than experimentally derived findings are generally used, so any comparison of the theories is mostly based on the internal logic of the arguments and their concordance with current understanding of more fundamental genetic research. For the purpose of this paper, the terms behavioural traits and personality traits, although not identical, are used interchangeably.
When considering a role for natural selection in developing personality traits the problem that arises is how to account for the wide variation in expression of these traits, where only the most extreme presentations appear to be disadvantageous and thus rare (Buss, 2008; Nettle, 2006; Penke, Denissen & Miller, 2007). For example, the trait of openness to experience has a very wide range of expression, from astronauts to the contemplative monk and everything in between.
Attempts to understand the existence of such large individual variation within personality has
References: Bouchard, T.J. Jr. & Loehlin, J.C. (2001). Genes, evolution and personality. Behavior Genetics, 31, 243-273. Bouchard, T.J.Jr. & McGue, M., 2003. "Genetic and environmental influences on human psychological differences." Journal of Neurobiology, 54, 4–45. Buss, D. M. (2008). Human nature and individual differences: Evolution of human personality. In O. P. John, R. W. Robins & L. A. Pervin (Eds.), Handbook of Personality: Theory and Research. New York: The Guilford Press. Buss, D.M. (2009). How can evolutionary psychology successfully explain personality and individual differences? Perspectives on Psychological Science, 4, 359 Cosmides, L. & Tooby, J. (2006). Evolutionary psychology: a primer. Extracted 23 March 2006 from http://www.psych.ucsb.edu/research/cep/primer.html Tooby, J. & Cosmides, L. (1990). On the universality of human nature and the uniqueness of the individual: The role of genetics and adaptation. Journal of Personality, 58, 17-67. Nettle, D. (2006). The evolution of personality variation in human and other animals. American Psychologist, 61, 622-631. Pinker, S. (2002). The blank slate: The modern denial of human nature. London: Penguin Books. Sterelny, K. & Griffiths, P.E. (1999), Sex and death: an introduction to philosophy of biology. The University of Chicago Press: Chicago and London.