Validation of the Mini-IPIP6 Short-Form Personality Inventory: Honesty-Humility Predicts Cooperation in Economic Games

Abstract

This study validated the Mini-IPIP6 short-form measure of Honesty-Humility to predict cooperative behaviour in online economic games. A subsample of participants from the New Zealand Attitudes and Values Study completed four online economic games for money, in addition to the Mini-IPIP6 six-factor personality inventory (N = 979). Cooperative behaviour was modelled as a latent variable reflecting behaviour across the four games. Honesty-Humility was the sole personality dimension associated with cooperative behaviour, even after adjusting for relevant demographics (including gender, age, ethnicity, socio-economic status, education and religiosity). Consistent with the hypothesised adaptive benefits of Honesty-Humility (i.e., gains from cooperation, mutual help and non-aggression), people higher in Honesty-Humility cooperated more with anonymous others in online economic exchanges for money when there was a risk of exploitation. Given the nature of the games, people higher in Honesty-Humility tended to earn more money if their partner cooperated, but less if their partner defected. These results validate the Mini-IPIP6 measure of Honesty-Humility and support its convergent and discriminant validity. These results highlight the predictive validity of the Mini-IPIP6 measure of Honesty-Humility and show it is reliably associated with cooperative behaviour.