Oddly enough, killer whales display personality traits similar to those of humans and chimpanzees, according to new research.
These shared traits include playfulness, cheerfulness, and affection, said the study conducted in Spain and published by the American Psychological Association in the Journal of Comparative Psychology. Researchers analyzed the personality traits of 24 captive killer whales (Orcinus orca) at SeaWorld Orlando, SeaWorld San Diego and the Loro Parque zoo in Tenerife, Spain.
Trainers and other staff working closely with the killer whales completed surveys ranking each animal on a list of 38 personality traits. Among these traits are playfulness, bravery, independence, sensitivity, stubbornness, and protectiveness. Those traits were analyzed and compared with other studies of the same personality traits for humans and chimps.
The study used the "five-factor model," which is a common personality measure. This method assesses five personality dimensions: extraversion, conscientiousness, agreeableness, dominance, and carefulness. The model developed over 80 years ago describes personality traits using a combination of single adjectives or descriptive phrases.
Researchers found the personality traits of killer whales are similar to those of both humans and chimpanzees but more similar to chimpanzees. Killer whales are similar to chimpanzees and humans for the extraversion factor (that is, playful, gregarious and sociable).
Chimpanzees and killer whales also shared a number of personality traits for conscientiousness (constant, stubborn and protective) and agreeableness (patient, peaceable and not bullying), along with a few personality traits relating to dominance.
The findings might suggest some evolutionary convergence where the personality traits of killer whales and primates are similar because of the advanced cognitive abilities required for complex social interactions.
Killer whales can live into their 90s in tightly knit pods that hunt together and share food; exhibit advanced communication skills and cooperation.
This is the first study to examine the personality traits of killer whales and how they relate to us and other primates, said Yulán Úbeda, the lead researcher. Úbeda is also a doctoral student in psychology at the University of Girona in Spain.
Úbeda said these similar personality traits may have developed because they were necessary to form complex social interactions in tightly knit groups that we see in killer whales, humans, and other primates. Killer whales aren't small whales but are the largest member of the dolphin family.
Past research has shown captivity can alter the personality of killer whales. Captivity will increase neuroticism and aggression, and cause physical changes such as dorsal fin collapse.
