By Emma Young
Memory complaints are fairly common among elderly people. Together with low participation in cognitively demanding activities, such as reading or doing crosswords, they can predict future declines — including the risk of developing dementia.
It might seem likely, then, that people with poorer cognitive functioning may report more problems, and may be less able to engage in (and so benefit from) reading or other stimulating activities. However, a new paper, published in Psychology and Aging, suggests that another factor is more important in predicting both these complaints and engagement in stimulating activities: personality.
The researchers, led by Patrick Hill at Washington University in St Louis, analysed data from 136 Swiss older adults, with an average age of about 70. (The data came from a bigger study into how the everyday behaviour of older people is linked to maintaining or improving wellbeing and health). The participants first completed a series of lab-based cognitive tasks, including memory tests, and self-report questionnaires, which included an assessment of the “Big Five” personality traits. Then, at the end of each of the next ten days, they used smartphones to report on any cognitive complaints during that day (e.g. “I misplaced or lost an object such as keys or glasses”), and also instances of cognitive engagement (e.g. “I enjoyed thinking about a complicated problem”).
Taking into account each participant’s age, education level and subjective health, the team then looked at how initial cognitive task results and personality trait scores might relate to the subsequent smartphone data.
They found that the number of daily cognitive complaints was significantly correlated with scores on all of the personality traits, but just one of the measures of cognitive performance (processing speed). Strikingly, scores on the two initial specific memory tests did not correlate with daily cognitive complaints. (This somewhat surprising observation is in fact supported by recent work that suggests our cognitive self-perceptions are relatively distinct from our actual performance).
When all of these variables were put into a model, however, only one factor emerged as being key. This was openness to experience, a personality trait that entails a liking for intellectual and artistic pursuits, and a willingness to try new things. Participants who initially scored higher for openness went on to report, on average, fewer cognitive complaints each day, and also more, and more varied, cognitive engagement.
There may be two reasons for this, the researchers suggest. Firstly, measures of openness tap into a person’s self-perceptions of their intellectual ability and creativity. People with a stronger belief in their intellectual capacities may perceive fewer cognitive issues in daily life. Secondly, people who are more open are of course more willing to engage in varied novel experiences. Because they enjoy intellectual activities, they may be driven to think more, and in more different ways — and this could protect against cognitive decline. In fact, there are other recent findings that diversity in cognitive activity, rather than total time spent in these kinds of tasks, may be more beneficial for cognitive performance in older age.
The work also suggests that in understanding why some interventions work better for some older people than others, personality traits should be taken into account. Also, interventions that encourage openness may potentially be more effective.
However, as the researchers themselves add, all of the personality traits, demographic variables and initial cognitive performance measures only account for a small amount of the differences in the level of cognitive complaints and engagement between people. The team would like to see more work to drill into potential links with personality in finer detail. But other factors that are yet to be well-characterised — levels of stress, perhaps — may well turn out to be far more important.