Just how stable are our personalities over our lifetime? Do we have roughly the same personality traits in old age as we did when we were teenagers?
Most studies that have explored that intriguing question have suggested the answer is yes, our personalities do remain fairly consistent across the decades. But those studies have covered relatively short periods — from childhood to middle age, for example, or from middle age to old age.
Recently, a team of researchers from the University of Edinburgh released findings from a much longer study on personality, one that followed people for 63 years. The study found — much to its authors’ own surprise — that we are remarkably different people in old age than we were in our youth.
“Personality in older age may be quite different from personality in childhood,” the study’s authors write.
The researchers started with personality data collected in 1950 on 1,208 Scottish 14-year-olds. The data came from their teachers, who were asked to assess six personality traits for each teen: self-confidence, perseverance, mood stability, conscientiousness, originality and desire to learn. The teens were also given an intelligence test.
The researchers then tracked down — in 2012 — as many of those Scottish students, who were now about 77 years old, as they could find. They located 635, of whom 135 (92 were women) agreed to have their personalities re-tested. This time the personality assessments — of the same six traits and using the same rating scale — were done twice: by the participants and by a close friend or family member whom each participant nominated for the task. Intelligence tests were also given, and the participants’ general well-being was measured.
The researchers had hypothesized before they started the study that the two sets of personality assessments would be consistent with each other, despite being conducted 63 years apart. But their analysis revealed no such correlation. That was true for each of the individual personality traits, as well as for a single underlying “dependability” trait, which the researchers based on the ratings for all six assessed items.
The data did show a positive correlation between the participants’ sense of well-being at age 77 and their “dependability” score at that age. Interestingly, however, their dependability score at age 14 was not related to their well-being six decades later.
As the authors point out, this finding appears to contradict that of previous research that has found “conscientiousness” (a trait related to “dependability”) in youth predicts well-being later in life.
The study also found some evidence of a life-long correlation between personality and intelligence. Not only did the children’s IQ results predict their “dependability” scores during adolescence, they also predicted their scores at age 77.
Not the final word
The idea that our personalities in old age are markedly different from what they were in adolescence may not be all that surprising, as the study’s authors explain:
Previous studies have demonstrated that personality is subject to a lifelong series of relatively small changes — particularly in adolescence and early adulthood, but continuing even into older age. As a result of this gradual change, personality can appear relatively stable over short intervals — increasingly so throughout adulthood. However, the longer the interval between two assessments of personality, the weaker the relationship between the two tends to be. Our results suggest that, when the interval is increased to as much as 63 years, there is hardly any relationship at all. If so, personality changes only gradually throughout life, but by older age it may be quite different from personality in childhood.
Still, this isn’t the final word on this topic, even if it is the longest-ever personality study. For the study comes with all sorts of caveats, as psychologist and journalist Christian Jarrett outlines in his summary of it for the British Psychological Society:
[A] psychology study covering such a long period of time faces many hurdles, among them the fact that personality theory has changed a lot over the decades. Today, there’s a near-consensus that personality is best conceptualised as being made up of five main traits (including Extraversion, Neuroticism etc) but that wasn’t the case back in 1950, which is part of the reason for the rather superficial and incomplete assessment of personality. It’s possible that if the participants had been assessed on a comprehensive, modern personality scale at age 14 and again at age 77, that we would see at least some correlation in scores.
Other methodological problems include the fact the teachers’ ratings of the teens were likely biased by their knowledge of the teenagers’ academic prowess (indeed, the personality scores they gave the teens correlated with the teens’ IQ; though even after attempting to “correct” for this in some complex analysis, there was still little evidence of personality stability across the decades). Yet another problem is that the sample that the researchers were able to reach in 2012 was a highly selected subgroup of the original sample, scoring much higher on average on dependability and intelligence: this may also have affected the ability to detect signs of personality stability. All of which makes it very difficult to interpret these new findings, interesting though they are.