To explore whether the possession of pets is related to a nation’s tendency to be violent, the ownership of cats & dogs in 15 industrialized nations was correlated with rates of suicide & homicide for 1978 & national scores for anxiety & extraversion based on social indicators such as caffeine consumption & psychiatric patients/capita. Neither ownership of cats nor dogs was related to the suicide rate, but rates of ownership of cats & dogs were associated with homicide rates. Pet ownership was related to national indices of extraversion but not to national indices of anxiety. (4 refs.)