Psychologists often focus on five traits — called the “Big Five” — to describe personality. These are: openness to experience, conscientiousness, extroversion, agreeableness, and neuroticism.
Known by the acronym “OCEAN,” psychologists and researchers consider these traits to represent core personality characteristics.
Now, a team of neurologists from the Albert Einstein College of Medicine in New York City has investigated the degree to which they may or may not be associated with predementia syndromes.
The researchers found that neuroticism increases the risk of nonamnesic mild cognitive impairment by 6%. Openness has the opposite effect, reducing the risk by 6%.
The study appears in the Journal of the American Geriatrics Society.
The study looked at the effect of personality on two syndromes that experts consider potential precursors to dementia. The first is motoric cognitive risk (MCR) syndrome, and the second is mild cognitive impairment (MCI) syndrome.
An individual with MCR will have a reported slight cognitive decline and either an objectively measured slow walking speed or an increased time in a five-times-sit-to-stand (FTSS) test, though some researchers question the use of the latter marker.
According to the Alzheimer’s Association, about 15–20% of people aged 65 and older have MCI. The association defines the syndrome as “a slight but noticeable and measurable decline in cognitive abilities, including memory and thinking skills.”
There are two types of MCI: aMCI, which involves some degree of amnesia, and naMCI, which does not.
The current study is not the first to examine the associations between the Big Five personality traits and cognition.
However, the study’s authors were interested in the clarification of earlier, sometimes inconsistent, research findings.
They note that research has previously tied lower levels of openness to MCI and Alzheimer’s and associated cognitive decline with neuroticism and conscientiousness.
The inconsistent research also includes some studies that link lower levels of agreeableness to dementia and others that do not.
The study analyzed data from adults aged 65 and older who were participating in the Albert Einstein College of Medicine’s Central Control of Mobility in Aging (CCMA) study.
Individuals from New York’s Westchester County who had voted in local or national elections within the last few years received an invitation to participate in the CCMA study. Researchers subsequently screened the candidates for eligibility.
In-person visits took place at the research center at Montefiore Medical Center in New York City. Each participant underwent comprehensive cognitive, psychological, and mobility assessments.
The team followed the participants at yearly intervals over the course of the research, from June 2011 to August 2018.
At the start of the study, these individuals completed the Big Five Inventory (BFI), a self-reporting questionnaire that identifies personality traits. They also completed tests for cognitive function.
Of the 588 potential participants, 12 did not complete the BFI, 26 lacked complete cognitive test data, and 9 were found to have dementia. Of the remaining 541 participants, 58 had MCI, 22 had MCR, and 17 had both MCI and MCR. The participants who had both MCI and MCR were ineligible for the study.
Over the course of the research, 38 participants developed MCR, and 69 developed MCI: 28 aMCI and 41 naMCI.
In the final analysis, the researchers did not use data from those who developed predementia less than 2 years into the study.
The study data confirmed the previously reported association of neuroticism with the development of naMCI, but not that of aMCI or MCR. In addition, openness reduced the likelihood of naMCI.
“These findings provide evidence of a distinct relationship between personality traits and development of specific predementia syndromes,” the study authors write.
The authors frame neuroticism and openness as problem and solution, respectively:
“These findings are consistent with previous studies that indicated neuroticism is a risk factor for cognitive impairment, and openness provides a protective effect against cognitive impairment.”
– Study authors
As far as the other personality traits go, any connections are less clear. The authors suggest two possible reasons for the continuing unclarity.
First, “specific personality traits are associated with decline, in particular, cognitive domains related to discrete predementia syndromes.” It is possible that personality traits that the participants self-reported are themselves the result of aging.
BFIs that the same individuals completed at a younger age may well not have produced the same personality profile.
If this is so, “personality traits [may be seen more as] markers of decline in specific areas of cognitive function and may reflect distinct biological pathways in the transition from normal cognition to specific predementia syndromes.”
Second, it is possible that the reported personality traits are individuals’ adaptations to the loss of cognitive function. The study’s results may thus “indicate that personality plays a role in transition to predementia syndromes.”
As this research looks at the transition to predementia, these traits may not affect the transition from predementia to dementia.
“Studies in younger cohorts with longer follow-up are needed to further explore these issues,” conclude the authors.
