Summary. Research from developmental psychology is suggesting that personality traits are inherently stable across a lifetime. Some characteristics may explain actual behavior or predict future development. This post, however, examines the question related to how much of our underlying personality is “nature or nurture.” In summary, genetic factors are independent of age and sex influencing character stability during childhood, while environmental factors are largely contributing to changes during adolescence and adulthood. Child rearing, culture, and health are significantly contributing to the changes that occur besides natural constancies.
Genetic and Environmental Influences on Personality
Freud’s psychosexual mental processes attempting to explain the psychological development and Eysenck’s explanation looking after brain structures and functionality are opposed to personality theories that are more emphasizing the long-lasting influences of exogenous factors such as social adaptation and family environment factors (Briley & Tucker-Drob, 2014; Pulkkinen, 2009). Both genetic inheritance and external factors are preserving or changing personality (Briley & Tucker-Drob, 2014, p. 1303). According to Blatný, Millová, Jelínek, and Osecká (2015), personality traits related to malleability are predominantly at work in adolescence. The influence of the environment increases in adulthood (Bleidorn, Kandler, & Caspi, 2014). Consequently, the family environment and socio-economic factors have little influence on the genetically inherent personality traits (Hur, 2007). This, of course, does not mean that such influences may not shape behavior, as we all can observe how persons respond to the environment, albeit according to one’s characteristics. In other words, genetics is responsible for stability, and the environment for change in individual traits during late adolescence respectively early adulthood (Bratko & Butkovic, 2007). Macaskill, Hopper, White, & Hill (1994) found that Psychoticism and Neuroticism are mostly depending on genetic factors and not age and gender, while this wasn’t the case for extraversion.
(Environmental) Factors Causing Changes in Personality Traits
Personality traits are considered to be relatively consistent over time (Briley & Tucker-Drob, 2014). Environmental factors are estimated to influence change in psychological traits for up to 100% during adolescence to early adulthood (Bratko & Butkovic, 2007). Considering an extended period (10 – 12 years) genetic influences may contribute to change too to some extent (Bratko & Butkovic, 2007). According to Secular changes in personality (2013), it matters during what cultural époque one is living as 75-year-olds after 2000 are more extroverted than groups of the same age back in the 1970s. Traumatic experiences in childhood can be another source triggering personality change manifesting later on in life (Li, Wang, Hou, Wang, Liu, & Wang, 2014). The existence of illness during adolescence may also impact later psychological development and on the trait level that means that increased neuroticism in the form of ill feeling goes together with the health of individuals (Wilson, Wrench, McIntosh, Bladin, & Berkovic, 2009). Similarly, developmental psychology today can verify the presence of adult personality disorders already in childhood (Lenkiewicz, Srebnicki, & Bryńska, 2016).
Although personality psychology’s progress in longitudinal lifespan personality development studies (Bleidorn et al., 2014), further research is needed to understand better the interplay of genetic and environmental factors related to their influences on psychological trait development (Pulkkinen, 2009).
Blatný, M., Millová, K., Jelínek, M., & Osecká, T. (2015). Personality predictors of successful development: Toddler temperament and adolescent personality traits predict well-being and career stability in middle adulthood. Plos ONE, 10(4),
Bleidorn, W., Kandler, C., & Caspi, A. (2014). The behavioural genetics of personality development in adulthood—Classic, contemporary, and future trends. European Journal Of Personality, 28(3), 244-255. doi:10.1002/per.1957
Bratko, D., & Butkovic, A. (2007). Stability of Genetic and Environmental Effects from Adolescence to Young Adulthood: Results of Croatian Longitudinal Twin Study of Personality. Twin Research & Human Genetics, 10(1), 151. doi:10.1375/twin.10.1.151
Briley, D. A., & Tucker-Drob, E. M. (2014). Genetic and environmental continuity in personality development: A meta-analysis. Psychological Bulletin, 140(5), 1303-1331. doi:10.1037/a0037091
Hur, Y. (2007). Evidence for Nonadditive Genetic Effects on Eysenck Personality Scales in South Korean Twins. Twin Research And Human Genetics, (2), 373.
Lenkiewicz, K., Srebnicki, T., & Bryńska, A. (2016). Mechanisms shaping the development of personality and personality disorders in children and adolescents. Psychiatria Polska, 50(3), 621-629. doi:10.12740/PP/36180
Li, X., Wang, Z., Hou, Y., Wang, Y., Liu, J., & Wang, C. (2014). Effects of childhood trauma on personality in a sample of Chinese adolescents. Child Abuse & Neglect, 38788-796. doi:10.1016/j.chiabu.2013.09.002
Macaskill, G. T., Hopper, J. L., White, V., & Hill, D. J. (1994). Genetic and environmental variation in Eysenck Personality Questionnaire scales measured on Australian adolescent twins. Behavior Genetics, 24(6), 481-491. doi:10.1007/BF01071561
Pulkkinen, L. (2009). Personality—A resource or risk for successful development. Scandinavian Journal Of Psychology, 50(6), 602-610. doi:10.1111/j.1467-9450.2009.00774.x
Secular changes in personality: study on 75-year-olds examined in 1976-1977 and 2005-2006. (2013). International Journal of Geriatric Psychiatry, (3), 298. doi:10.1002/gps.3825
Wilson, S. J., Wrench, J. M., McIntosh, A. M., Bladin, P. F., & Berkovic, S. F. (2009). Personality development in the context of intractable epilepsy. Archives Of Neurology, 66(1), 68-72. doi:10.1001/archneurol.2008.532
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Developmental Personality sequences are complex. There are more variables than can be integrated into a personality study to add to the confidence level needed to make a viable prediction in any research hypothesis. Surprisingly, personality assessments, in my professional opinion, are not well correlated based on family or environment, it is our DNA, like hair color, eye color, and so forth, that is key to understanding personality. In my opinion personalities don’t change, they are just expressed differently overtime, because the traits are all there from conception. Exceptions are severe emotional trauma, psychosis, and physical trauma. However, likes and dislikes can be presented with some degree of accuracy as a correlation with professional type-matching, like the Myers-Briggs personality test. Thank you for a great post! I love research. My master’s is in clinical research. K. D. 🙂
Thank you for your value adding feedback. Your point is much in line with research confirming the inheritability of personality traits, and I agree with you that there are so many factors to be considered to make accurate predictions. That’s why psychometric tests are about ‘tendencies,’ rather than absolute statements. Good to know your background, thanks a lot!
Mathias, good to hear from you and I enjoyed your article, really put together so well. Yes, tendencies are all we can look at in research right now regarding personality traits and generally, absolutes are never predicted in research, only probabilities and percentage. Personality studies do give us a little bit to follow for more advanced studies, so those studies do have merit. Technology is developing so rapidly now, that DNA will reveal much more than it does now. I love research. I taught clinical research at FAU and worked in Clinical Research Cancer at Emory University in Atlanta, Ga.
Hi, Karen. Thanks a lot! I agree, and indeed, technological progress is important to advance research, but not only as I think we are not entirely explainable mechanistically (i.e., genetically, (neuro-) biologically). Our personality may be determined by a “dynamic interactions among biological, psychological, behavioral and social factors.” – US Research Council Committee. I find your background impressive, and I appreciate to stay connected!
I agree with you!! And yes, we are genetically and biologically, culture, birth place, and we are complex beings. All of those variables impact us. In fact, even food chemistry can play hectic with our personality in our developmental stages and through out our lives. You might find it interesting. Chemistry, Botany, and food science are favorite studies of mine. Yet, even all of this does not explain, the un-explainable. K D 🙂
Love this article. I could talk about the nature versus nuture debate all day. Although, I have over the past few years taken the Myers Briggs test with varying results. Sometimes I’m an ENFJ, othertimes I’m an INFP! Strange, right?
Thank you. It’s interesting indeed, and still a debate as you mention! Given the influence of “nurture,” it is not surprising to me that personality tendencies and especially shown behavior can differ over time as personal development changes its focus (e.g., professional vs. private) and environment (e.g., different jobs and responsibilities) with age, life events, and many more influencing factors. As in your case, maybe it is a typical development to become more introvert, and perception focused with less extrovert and judging tendencies over time, while the use of intuition and feelings can remain more basic characteristics.
Ahh very interesting, thanks Mathais I hadn’t thought about like that – I did often feel back when I was showing up more as an extrovert that I was “putting it on” at times as extroversion is often championed as preferable in Western cultures. Thanks again and looking forward to reading more of your posts.
very interesting Article keep it up