Personality traits and body weight: Evidence using sibling comparisons

Area of Science:

• Behavioral genetics
• Psychology
• Public Health

Background:

• Personality traits are associated with body weight.
• This relationship may be influenced by unobserved family factors like genetics.

Purpose of the Study:

• To determine if the link between Big Five personality traits and body weight in young adults is spurious due to shared family background.
• To investigate the role of family-level characteristics in the personality-body weight association.

Main Methods:

• Utilized data from the National Longitudinal Study of Adolescent to Adult Health (Add Health).
• Employed family-fixed effects analysis to control for unobserved sibling and family characteristics.
• Analyzed associations between Big Five personality traits and body weight, including body mass index (BMI) and obesity risk.

Main Results:

• Conscientiousness demonstrated a robust association with lower body weight and reduced obesity risk, independent of shared family background.
• A one-standard-deviation increase in conscientiousness correlated with a 0.89 decrease in BMI and a 12% lower probability of obesity.
• The association between conscientiousness and obesity was more pronounced in women and Hispanic individuals.

Conclusions:

• The link between conscientiousness and reduced body weight is not confounded by unobserved family characteristics.
• Interventions aimed at developing conscientiousness may have positive spillover effects on obesity reduction.
• Personality traits offer a potential target for public health strategies addressing obesity.