Canine analogs of human personality factors.

Analysis of the behavioral traits of 56 breeds of dog produced three factors with some similarities to the popular five-factor model of human personality: (a) reactivity--surgency, (b) aggression--disagreeableness, and (c) trainability--openness. Canine and human personality similarities are argued to have their origin in biogenetic factors stemming from common evolutionary sources and from canine breeding for human compatibility and assistance with human tasks. Each of the three canine factors was shown to have a highly visible morphological indicator between breeds of dog. Reactivity--surgency was related to overall size, aggression--disagreeableness was related to having pointed ears, and trainability--openness was related to the ponderal index.