Conscientious people tend to have larger brain volumes in critical areas, research reveals.
People who are careful, efficient and self-disciplined, have more gray matter in their frontal and medial temporal brain regions.
These areas are critical for many functions, including reasoning, taking action and controlling the emotions.
The link could be explained by conscientious people being more likely to look after their health: so, their brains shrink less with age.
In contrast, neurotic people — those who tend to get nervous or sad — have smaller brain volumes in these regions.
This link may be due to chronic stress causing brain shrinkage.
The conclusions come from a study including 79 people aged 44 – 88 who were given personality tests and brain scans.
Dr Denise Head, study co-author, explained the results:
“Our data clearly show an association between personality and brain volume, particularly in brain regions associated with emotional and social processing.
This could be interpreted that personality may influence the rate of brain aging.”
One of the ways being neurotic may affect brain volume is through stress.
Chronic stress does all sorts of damage to the brain over the years.
Dr Jonathan Jackson, the study’s first author, explained:
“We assumed that neuroticism would be negatively related to structural volume.
We really focused on the prefrontal and medial temporal regions because they are the regions where you see the greatest age changes, and they are also seats of attention, emotion and memory.
We found that more neurotic individuals had smaller volumes in certain prefrontal and medial temporal parts of the brain than those who were less neurotic, and the opposite pattern was found with conscientiousness.”
It is not clear from this study that being neurotic, or lacking conscientious, causes reduced brain volume.
One theory is that the early stages of Alzheimer’s may prompt a change in personality.
Dr Jackson said:
“It might be that changes in personality track onto those people more likely to develop Alzheimer’s.
We know that there are degenerative processes going on before the diagnosis of Alzheimer’s.
We want to be able to see if the subtle personality changes might be particular to an early clinical picture and possibly see if one can predict who will become demented based on personality changes.”
The study was published in the journal Neurobiology in Aging (Jackson et al., 2012).