Numerous studies suggest that human personality and great ape personality have a common structure that can be described through the human Five Factor (FFM)/Big Five model, оr some of its dimensions, albeit after some adaptations. I argue that such conclusions are unwarranted. First, the human FFM contains facets-such as aesthetics, ideas, values, modesty, dutifulness, deliberation, and more-that have not been convincingly detected in animals. Second, I show that great ape personality traits are not structured like their postulated human FFM/Big Five equivalents. Based on very relaxed criteria, the shared invariant structure (percentage of indicators with the highest loadings consistently on the same factor) in humans and great apes is just below half at best and often only about one-third. Great ape personality models are not structured equivalently either, suggesting that each species has its own personality structure. Even FFM/Big Five-based studies of the same species do not yield invariant models. Consequently, neither the whole human FFM/Big Five nor its dimensions separately are appropriate for nonhumans. I propose that personality comparisons across species can be made more judiciously by focusing on approximations of single and simple human FFM facets (rather than whole complex traits) whose rough equivalents have been confirmed across all great apes, and some prototypes of which have emerged even in studies of cephalopods. This approach could allow meaningful comparisons of personality across species.
Michael Minkov (Fri,) studied this question.