How much does personality change over time?

A post I wrote on this topic in 2010 attracted a fair amount of interest. That might be explained by the provocative  title: ‘Once a neurotic always a neurotic?’ The view presented was that while personality is generally fixed by about age 30, there is some evidence of personality change among older adults, associated with such things as use of anti-depressant drugs, cognitive behavioural therapy and meditation.

Recent research has provided evidence that personality is much more variable than it was previously thought to be. The findings of some relevant research by Christopher Boyce, Alex Wood and Nattavudh Powdthavee are summed up in the title of their article: ‘Is Personality Fixed? Personality changes as much as “variable” economic factors and more strongly predicts changes to life satisfaction’. (The article has been published in ‘Social Indicators Research’).

The research uses data from the HILDA surveys, which in 2005 and 2009 asked 8,625 Australians questions designed to measure their personality according to the Big Five criteria: openness to experiences, conscientiousness, extraversion, agreeableness and neuroticism. The authors found substantial variation of all personality criteria between the surveys. The variation of agreeableness and neuroticism for the same individual was about half as great as the variation between individuals.

In their initial analysis the authors corroborated earlier cross-section research showing that some personality factors have large impacts on life satisfaction. They found that emotional stability (the opposite of neuroticism) had the greatest impact, followed by agreeableness and extraversion. The estimated coefficients on the personality variables were generally somewhat lower in the analyses focusing on the effects of changes over time suggesting to me that some of the apparent change in personality might be attributable to measurement error. Nevertheless, the implied impacts of change in personality are still relatively large by comparison with the impacts of the economic variables such as income and employment status.

What are the implications of the finding that individual life satisfaction may change substantially over time as a result of personality changes? The answer depends partly on how important we see life satisfaction in the context of the overall quality of life. For example, it is interesting to speculate that the phenomenon that Carol Graham describes as the happy peasant, frustrated achiever paradox – happiness declining for some people whose wealth is rising – could be attributable to personality change. People may choose to have opportunities for better education and higher incomes, even if this may result in some loss of contentment (perhaps as a consequence of personality changes).

It is difficult to consider the implications of changes in personality without knowing what causes personality to change. I found it surprising that the results suggest that the adverse impact of unemployment on life satisfaction is independent of personality change. (The estimated coefficient on unemployment remains unchanged when the personality variables are introduced into the analysis.)

 

Boyce et al speculate that personality change could be associated with environmental factors and that public policy could foster positive environments. However, the example they give of the possibility of personality change through improved availability of mental health services might have more to do with changing perceptions of experience and of identity than with changes in environmental factors.

It is possible that the effects of individual personality changes might tend to wash out in large samples. Those whose life satisfaction rises as a result of personality changes might be balanced by those whose life satisfaction falls.  But is not inevitable that this will happen. Perhaps pervasive changes in personality at an individual level might be reflected in changes at a national level in the extent of uncertainty avoidance or in the extent to which people are prepared to trust others.

It will be fascinating to see what light further research is able to shed on the causes and effects of personality changes.