The Personality You Develop Is the Personality You Seek |
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The nature versus nurture controversy is challenged by the “niche-picking” theory of life choices.
A large twin study of adults over the lifespan shows how personality consistency and change evolve.
Your niche may be where you begin your life experiences, but it needn’t define or constrain you forever.
How often have you heard (or said) that people don’t change their personalities once they pass childhood? Going even further, you’ve undoubtedly heard the view that people inherit their personalities just like they do their eye color. Josephine has “her mother’s stubbornness,” and Stewart’s flakiness comes directly from his father, say your family members. Maybe you agree with these “nature” views. Or perhaps you’re on the side of “nurture,” regarding Josephine’s stubbornness as the result of being spoiled by her parents and Stewart’s flakiness from the fact that he liked being the family clown, because it always got him attention and more than a few laughs.
The researchers who study personality in adulthood and later life long ago abandoned these ideas when the data didn’t match the myth. Still, there remains a considerable amount of mystery surrounding the question of why people’s personalities change. Josephine, as stubborn as she once was, has learned over time that it’s better to be more flexible. Stewart may have learned the hard way that flaky people don’t get promoted at work.
Niche-Picking and Personality Change
Once offered as a nature plus nurture alternative to each extreme, the more complex “niche-picking” proposal suggested that people’s personalities lead them to choose certain environments, which, in turn, further influence their personalities. Over time, their personalities mold even more to those environments. The upshot is that whatever continuity exists in personality across adulthood is due more to the effect of the environment they chose to inhabit rather than to an innately determined set of processes.
University of Southern California’s Christopher Beam and Emily Sharp (2026) were able to put the niche-picking principle to the test in the remarkable nearly 30-year Swedish Twin Study of Aging, The study’s goal was to test the relative contributions of heredity and the environment on long-term changes in personality by taking advantage of the repeated testing of personality that occurred over this time interval. Focusing on the three personality traits of neuroticism, extraversion, and openness to experience, the USC authors could evaluate the extent of P→E (that is, people picking environments) effects compared with simple heritability estimates based on the shared genetic variance between twins.
How P→E Plays Out over the Life Span
The authors performed extensive analyses comparing the effects of age, heritability, and P→E effects across the decades from 36 to 91 years old on each of the three traits. The findings showed that individuals gained in personality consistency the more they selected environments that matched their personalities. This was particularly so in middle adulthood for neuroticism and openness and for neuroticism and extraversion in later adulthood. People’s personalities shifted in response to environmental influences, but not straight across the board or for all ages.
Taking these one at a time, the findings for neuroticism suggested that “People’s tendencies to niche-pick have some role in explaining why some people become and remain more neurotic than other people at all stages of adulthood” (P. 14). The neurotic gravitates toward situations that reinforce that general tendency to worry and be anxious. Maybe these individuals become drawn to activities such as doomscrolling, where they seek out negative social media feeds, serving only to create more anxiety and fear about the future.
For extraversion, that tendency to be gregarious and warm, the P→E influences were strongest in the later years of adulthood among the oldest participants. Among the possible interpretations of this finding, the one that stands out the most appears to be the idea that in later life, extraverted people seek ways to continue to remain engaged with others. Rather than fall prey to social isolation and a life of quietude, older individuals already predisposed to high levels of extraversion feed on the need to socialize rather than put themselves away on the shelf.
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Finally, for openness, practically no P→E effects were observed in the later adult years. It appears, conclude the authors, that people make their choices early in life to develop an open and exploratory lifestyle. By the time they reach their later years, they’ve already established these patterns. The art-lover and poetry aficionado know early in life that they enjoy playing with ideas and creative themes. Continuing these patterns throughout life, there may be no room for openness to change any further.
Selecting Your Own Niche
The underlying theme of this comprehensive and innovative paper is that people don’t just fall prey to whatever nature or nurture throws their way. Depending on the point in life when P→E takes over, they actively select ways to express their personalities; once those patterns are started, they become self-perpetuating.
On the other hand, the magnitude of these effects never reached anything close to 100 percent, leaving much to be explained. Thinking back on Josephine, maybe she entered the adult realm of responsibilities with a pretty inflexible approach to life. She may even have sought those niche-type activities that would reinforce her unwavering sense of self-direction, such as becoming a store manager. Yet, leaving that room for variation, it may soon have become evident that she needed to be more adaptable to the needs of her employees.
Similarly, for Stewart, flakiness really only gets you so far. He may have drifted into a job or serious relationship without giving it much thought, only to find that he needed to shape up and become a bit more mature.
The good news about the USC study is that it shows that personality can and does modulate over adulthood, and not solely due to the ticking away of some type of genetic clock. You arrive in life with some features of your personality that reflect your inherited qualities, but as you move through life, these qualities interact with or may be outweighed by your life experiences.
To sum up, it may be somewhat comforting to live within the niche that you choose for yourself, but just as comforting to know that the niche need not limit your fulfillment.
Beam, C. R., & Sharp, E. S. (2026). Person–environment transaction underlying personality development in middle and late adulthood. Developmental Psychology. Advance online publication.