Yes and no, answer the scientists from the Institute of Ecology and Evolution of the Russian Academy of Sciences. The Laboratory of Population Ecology studied personality (stable individual characteristics of behavior) in two species of gerbils: the solitary midday gerbil (Merionesmeridianus) and the social Mongolian gerbil (M. unguiculatus).
In a specially designed battery of behavioral tests, reminiscent of agility competitions, gerbils were given the opportunity to run, jump, look for new objects, get scared and overcome fear, interact with a conspecific, and resist restriction of freedom. Interindividual differences in personality traits (boldness, curiosity, sociability, excitability and self-confidence) were stronger and more consistent in solitary midday gerbils, contrary to the hypothesis of social niche specialization.
It is an anthropocentric and economical assumption that personalities should be more strongly expressed in social species: each social niche has its own personality type. This saves time and energy on the distribution of social roles. That's what the theory says. However, so far the hypothesis has been tested on non-primate mammals twice: once receiving arguments “for”, once “against”. So now the score is 1:2.
The results were published April 16 in the journal PLOS ONE.