Not only humans have a personality. Scientists have long known that other animal species, including mammals, fish, and invertebrates, display considerable individual variation in behavior. This individual variation has been shown to have important ecological and evolutionary consequences. Research on animal personality has therefore received considerable attention, yet some methodological issues remain unresolved. It is important to develop reliable, time-efficient methods of personality assessment that can be applied across animal species.
Michaela Másílková and Martina Konečná from the University of South Bohemia and their colleague Alexander Weiss from the University of Edinburgh focused on the methodology of this cross-disciplinary research. They used cotton-top tamarins (Saguinus oedipus) as a study subjects. Tamarins are small, insectivorous, and highly social primates from tropical forests of South America. This study used captive-born tamarins living in five zoos in Czechia and Slovakia. The aim of the study was to find out how long does it take to assess the personality of tamarins by observing their behavior. Some experts believe that this method of personality assessment is too time-consuming.
Researchers observed the behavior of 20 tamarins for a total of 300 hours. First, they identified the behaviors that were stable over time. Then, they assess personality types of tamarins based on these behaviors and different periods of observation. The results shows five observational hours per individual are sufficient for reliable personality evaluation. Longer observation does not have to lead to any more accurate assessment. Thus, In the case of cotton-top tamarins, behavioral observation over relatively short periods of time can be used to assess personality and that longer observation periods may yield diminishing returns.
Másílková, M., Weiss, A., & Konečná, M. (2018). How long does it take? Reliable personality assessment based on common behaviour in cotton-top tamarins (Saguinus oedipus). Behavioural processes, 157, 59-67.