Now, who do you think you are?

Personality changes over time. We used to think that personality was fully developed by age 30 or thereabouts. Now there is evidence to show that personality changes across the life span.

By our 70s and 80s our personality may have undergone considerable change. If personality is assessed across the life span with smaller time intervals in between each assessment, then the changes are also small.

But when the interval between assessment of personality is increased the change increases dramatically. One study showed that with a gap of 60-plus years between assessment there was little relationship between the child’s personality and the older adult’s.

This indicates that personality changes are gradual and not obvious as they occur but that they are continuing to occur.

There are five personality traits that are common across cultures and ages.

These are extraversion, openness, neuroticism, conscientiousness and agreeableness.

Extraversion considers how a person interacts socially. It looks at the extent to which a person is outgoing and sociable.

Openness looks at the person’s curiosity about the world and willingness to try new things.

Neuroticism assesses the degree of emotional stability. If the person is moody or prone to sadness or stress they may score high on this trait.

Conscientiousness relates to a leaning towards being goal directed, organised and disciplined. It includes impulse control.

Agreeableness relates to how you are with others. People with high scores on agreeableness prioritise peaceful relationships and tend to be soft-hearted, friendly and compassionate.

Studies have shown that as we age there is a downward trend on all five traits except for agreeableness.

This means that older people, compared to their scores attained as younger people, had become less extraverted, less open, less neurotic, less conscientious. There is some evidence that indicates that men do not experience the lessening of extraversion as they age.

Considered together, these changes might suggest that as people age they become more content in their own company, less worried about what others think, more cautious about trying new things, less concerned about planning and organisation. On the trait of agreeableness, there is less clarity. It seems that in general it increases but for some it does not change.

Even though personality changes as we age it also stays stable relative to other people. So, if you were a highly extraverted 21-year-old who was always looking for company because you were more outgoing than your friends, then you are likely to still be more extraverted than your peers when you are in your mid 60s or 70s.

This contributes to the sense we often have that personality is stable rather than changing. As we age there are other factors that can impact on personality.

For example, agitation and anxiety commonly increase with age. This can lead to irritability and worry which influence perceived personality.

Cognitive decline, depression, medication and hormonal changes are some of the factors that can influence the expression of personality. Often they are slow changes if the conditions are also slow in developing.

The actress Betty Russell said that personality is not a predictor of character.

I like this simple statement. It opens another raft of questions and opportunity for debate but for me it is a reminder that despite our often-flawed personality, we can live to our values and be proud of who we are in the world.

Judy Rafferty is the author of Retirement Your Way, A Practical Guide to Knowing What You Want and How to Get It, at all good bookshops and online.