The National Institute on Aging did some very interesting analysis on a group of people they have been following for 50 years and tied a few key personality traits to measurements of adiposity: BMI score, waist size, body fat and hip size. They found some interesting, if not unexpected, correlations: impulsive and extroverted people tend to be fatter; and conscientious, disciplined, organized people tend to be skinnier. This makes sense because people who are impulsive tend to eat more, as do social butterflies since so many social events are based around eating and drinking. Disciplined people however, will have either the will power or coping mechanisms in place to navigate their daily life without over-indulging in calories or exercising enough. Note however, that the two sides aren’t mutually exclusive: disciplined people can be extroverted, and vice-versa.
The traits were taken from the Five Factor Model in psychology, which describes human personality by scoring subjects on each of five areas. From Wikipedia:
- Openness – (inventive/curious vs. consistent/cautious). Appreciation for art, emotion, adventure, unusual ideas, curiosity, and variety of experience.
- Conscientiousness – (efficient/organized vs. easy-going/careless). A tendency to show self-discipline, act dutifully, and aim for achievement; planned rather than spontaneous behaviour.
- Extraversion – (outgoing/energetic vs. solitary/reserved). Energy, positive emotions, surgency, and the tendency to seek stimulation in the company of others.
- Agreeableness – (friendly/compassionate vs. cold/unkind). A tendency to be compassionate and cooperative rather than suspicious and antagonistic towards others.
- Neuroticism – (sensitive/nervous vs. secure/confident). A tendency to experience unpleasant emotions easily, such as anger, anxiety, depression, or vulnerability.
What the researchers found was that people who scored high on the Neuroticism and Extraversion traits were fatter, and people who scored high on the Conscientiousness trait were skinnier. They went a little deeper though and made finer measurements of ‘facets’ in each of the five main personality traits, which gave them even more insight. These facets are more practical concepts to grasp, so here are the ones that had significant correlation to higher body fat — 0 means no correlation, 1 means complete correlation:
- 0.26 – Impulsiveness, the only facet of Neuroticism that was significant
- 0.13 – Warmth, part of Extraversion
- 0.12 – Assertiveness, part of Extraversion
- 0.07 – Positive Emotions, part of Extraversion
- 0.06 – Gregariousness, part of Extraversion
- 0.05 – Competence, part of Conscientiousness
- 0.05 – Excitement-seeking, part of Extraversion
And the facets that had significant correlation to lower body fat, meaning a negative correlation higher body fat:
- 0.12 – Order, part of Conscientiousness
- 0.10 – Self-discipline, part of Conscientiousness
- 0.09 – Straightforwardness, part of Agreeableness
- 0.08 – Activity, part of Extraversion
- 0.07 – Modesty, part of Agreeableness
- 0.05 – Deliberation, part of Conscientiousness
- 0.05 – Altruism, part of Agreeableness