The complex interrelations between traits and abilities took a BIG study to unpick.
If you think about how personality and smarts are linked in popular culture, a pattern may come to mind: you’ll get a cranky, evil, tortured or misanthropic genius – the brilliant reclusive scientist being one such trope – and a happy, open and outgoing fool more often than not.
Here comes science – with a big team effort, no recluses in sight – to burst that little stereotype.
This huge systematic review published in PNAS has sought to quantify the relationships between personality and cognitive ability to an unprecedented degree. The team calls the results “encyclopaedic”, which seems not unfair when you consider they looked at more than 1300 studies and did 3543 meta-analyses on a combined sample of more than two million people, examining 61,000 relations among 79 personality constructs and 97 cognitive abilities. It took them 13 years. (You can read the full summary paper here.)
The Back Page feels her remaining cognitive abilities seeping out through her ears at the thought. Here is a light jog through the most striking results.
Neuroticism involves feeling negative emotions, which interrupts higher cognition, the authors say. It makes sense, then, that neuroticism traits – with “aspects” of volatility and withdrawal and “facets” of anxiety, depression, negative affect, suspiciousness, and uneven temper – correlated negatively with cognitive abilities.
In particular, depression, uneven tempered, suspiciousness, and anxiety had large negative relations with nearly all “non-invested” cognitive abilities, i.e. everything except acquired knowledge (“invested abilities”) and general mental ability. This may reflect the enervating effects of neuroticism traits, the authors say.
Agreeableness – which involves getting along, co-operation, altruism and all that good stuff – had the weakest relations with cognitive abilities. But interestingly its aspects, compassion and politeness, went opposite ways in their correlation with cognitive ability: compassion positively, politeness negatively.
Politeness, the authors speculate “may require effortful inhibition of behaviour to avoid rude, manipulative, and belligerent behaviour, reducing cognitive resources available … Negative relations with acquired cognitive abilities may similarly result from psychological resources being directed to investment in social graces rather than knowledge accumulation in other domains.”
Conscientiousness was positively correlated with cognitive abilities overall. The aspect of industriousness was one of the stronger correlates of general mental ability, rugged individualism was positive with acquired knowledge, while orderliness was a bit more mixed (are you cleaning up your desk rather than working on the actual task at hand?). Cautiousness was negatively correlated with a range of acquired knowledge abilities, and routine seeking was negative all round.
Extraversion traits “reflect behavioural engagement with the external world and sensitivity to rewards”, the authors say, with aspects of assertiveness and enthusiasm, and facets of activity, dominance, positive emotionality, sensation seeking, and sociability.
Overall there was a barely-there positive correlation with cognitive abilities. The activity facet, however, had large positive relations especially with general mental ability.
Finally, openness traits – with aspects of intellect and experiencing, and facets including aesthetics, curiosity, fantasy ideas, need for cognition, introspection and variety seeking – are already established correlates of brightness, and this study confirmed a positive relation between global openness and general mental ability.
Drilling down, openness showed much stronger correlations with verbal abilities than quantitative ones, same with foreign language proficiency and knowledge in general science, social studies and arts and humanities. The intellect aspect was strongly positively related with verbal and quantitative abilities.
“Personality traits reflect different strategies for sensing, evaluating, and behaving,” the authors write, while cognitive abilities “explain how efficiently and proficiently goals are set, pursued, and achieved in complex environments.” Understanding how they interact to coordinate the use of finite resources towards achieving goals and generating new ones will “pave the way for improved theoretical explanations of human behaviour and applications that harness individuals’ potential and improve the human condition”.
The Back Page would be in a lofty mood too if we’d just handed in a paper like this … but as it is, we’re off to bathe our sore brain in pop cultural stereotypes.
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