Blood type and personality

Abstract

This study investigated possible relationships between blood types and personality within a normal population. Evidence from published studies claiming associations between blood type and personality is scanty, conflicting, and characterised by unequal cell sizes. This study predicted that compared to those with other blood types, blood Type B individuals would be higher on neuroticism, blood Type O individuals would be higher on extraversion and optimism, blood Type A individuals would be higher on agreeableness and blood Type AB individuals would be higher on conscientiousness. A main effect for gender on neuroticism and an interaction effect for gender and blood Type B on neuroticism were also predicted. Participants comprised a quota sample of blood donors—180 males and 180 females. Thirty males and 30 females from each of the four blood types were included in the final analysis. A version of the big-five factor personality inventory developed by Goldberg, and the Life Orientation Test Revised were administered. MANOVA results showed that the combined dependent variables were not significantly affected by blood type, nor by gender, nor were there any interaction effects. No relationship between blood type and personality is supported by this study. Methodology of previous studies is reviewed and implications of the findings considered.