The study, which began collecting data in 1997, involved 1,954 people from retirement communities, church groups, and subsidized nursing homes with no formal diagnosis of dementia. They all agreed to undergo an annual cognitive assessment after the initial assessment.

Researchers said personality traits reflect long-term thinking and behavioral patterns, which may cumulatively affect healthy/unhealthy behaviors and thinking patterns across the lifespan.

They believe that the accumulation of life experience may make people more susceptible to certain diseases, such as mild cognitive impairment, or cause individual differences in individual tolerance to aging-related neurological changes.

The research team focused on the effects of “conscientiousness”, “neuroticism”, “extroversion” and other traits on cognitive function after aging.

According to research, participants with high “conscientiousness” scores were described as hard-working and responsible; participants with high “neurotic” scores were often emotionally fluctuating, anxious, and depressed. People with high “extroversion” tend to be talkative and assertive.

The study found that people with high conscientiousness or low neuroticism were less likely to experience mild cognitive impairment during the study period.

Conscientiousness scores ranged from 0 to 48, a researcher said, and those who scored about 6 points higher had a 22 percent lower risk of general cognitive function transitioning to mild cognitive impairment.

In addition, those with neuroticism scores that ranged from 0 to 48, with scores roughly 7 points higher, had a 12 percent higher risk of developing cognitive impairment,

As for people with high extroversion, the time to maintain normal cognitive function is usually longer than others.

researchers added that the study had its limitations, including that the participants were predominantly Caucasian, as well as highly educated. The study found no link between specific personality traits and longevity.

(Source: The Hill, APA)