Hostile young adults may experience thinking, memory problems in middle age

"We may not think of our personality traits as having any bearing on how well we think or remember things, but we found that the effect of having a hostile attitude and poor coping skills on thinking ability was similar to the effect of more than a decade of aging," said study author Lenore J. Launer, PhD, with the National Institutes of Health in Bethesda, Md., and a member of the American Academy of Neurology.

For the study, 3,126 people were asked questions that measured their personalities and attitudes, ability to cope with stress, and memory and thinking abilities at the start of the study when they were an average age of 25. Cognitive abilities were measured again when they were an average age of 50.

To measure hostility, the questions about personality assessed aggressive behavior, a lack of trust for others and negative feelings associated with social relationships. Another question looked at effortful coping, which was defined as actively trying to reduce stress despite repeated barriers to success. For the analysis, participants were divided into four groups based on their level of hostility and effortful coping.

The study found that for both personality traits, people with the highest levels of the traits performed significantly worse on tests of thinking and memory skills 25 years later than people with the lowest levels of the traits. For example, on a test that asks people to recall a list of 15 words, people with the most hostility in young adulthood remembered 0.16 fewer words in mid-life than people with the least hostility. Those with the highest level of effortful coping remembered up to 0.30 fewer words than those with the lowest level of effortful coping.

The results were the same when the researchers adjusted for factors such as depression, negative life events and discrimination. When researchers adjusted for cardiovascular risk factors such as diabetes and high blood pressure, the results stayed the same for the coping trait but the relationship between hostility and thinking skills was reduced.

Launer noted that the study is observational. It does not prove that hostile attitudes and poor coping skills cause memory and thinking impairment; it only shows the association.

"If this link is found in other studies, it will be important to understand whether these personality traits are amenable to change that would lead to interventions that promote positive social interactions and coping skills to see if they could play a role in reducing people's risk for memory and thinking problems in middle age," she said.