To test hypotheses formulated by Ones and Viswesvaran (1997), a cohort of 47 selected volunteer overseas development workers from New Zealand completed the NEO PI-R ‘Big Five’ personality inventory. In line with hypotheses, these workers were significantly higher than population norms on openness and its six subfacets, and on agreeableness and the subfacet of tender-mindedness, but contrary to hypotheses, they were not significantly different on either neuroticism or conscientiousness. The article argues for further research in this field.