Researchers find dolphins to be far more similar to humans than previously thought.
For those who have ever observed monkeys and apes – our closest evolutionary cousins – in the wild, in a zoo, or on television, it is apparent that in many ways, their personalities mirror our own. Scientists like Dr Blake Morton, a Lecturer of Psychology from the University of Hull, suggest that such similarities are due to humans and other primates having similar evolutionary histories. Like humans, for example, many other primates have evolved to be relatively intelligent and form societies comprised of friendships, families, and cultural traditions.
To test this idea further, Dr Morton and a team of other researchers studied personality in bottlenose dolphins.
Dr Morton said: “Dolphins were a great animal for this kind of study because, like primates, dolphins are intelligent and social. We reasoned that if factors such as intelligence and gregariousness contribute to personality, then dolphins should have similar personality traits to primates.”
Human behaviour comprises five personality traits, which, appropriately for a study about dolphins, form the acronym OCEAN. These are: Openness (e.g. curious, playful, and active), Conscientiousness (e.g. reliable, predictable, and self-controlled), Extraversion (e.g. friendly, outgoing, and sociable), Agreeableness (e.g. kind, affectionate, and helpful), and Neuroticism (e.g. anxious, erratic, and emotionally unstable).
Research shows that monkeys and apes have the same or similar personality traits as humans, but Dr Morton’s team are the first to investigate if the same traits exist in dolphins.
The researchers found that dolphins, like primates, have personality traits related to curiosity and sociability, specifically Openness and a personality trait that is a blend of Extraversion/Agreeableness. Dolphins, though, have very low neuroticism.
Dr Morton said: “Dolphins, like many primates, have brains that are considerably larger than what their bodies require for basic bodily functions; this excess of brain matter essentially powers their ability to be intelligent, and intelligent species are often very curious.
“Throughout our lifetime, we interact and form relationships with a wide variety of people – dolphins do the same with each other. Collectively, being smart and social, regardless of what ecosystem you live in, may play an important role in the evolution of certain personality traits.”
Their study, entitled Personality Structure in Bottlenose Dolphins (Tursiops truncatus), began in 2012 and was published this year in the Journal of Comparative Psychology.
The authors collected data on 134 dolphins, of which 56 were male and 78 were female, from different facilities across eight countries, including Mexico, France, the United States, Curacao, the Netherlands, Sweden, the Bahamas, and the Cayman Islands.
Despite the study providing new insight into how our own personality traits might have evolved, Dr Morton emphasises that this is only the beginning in terms of identifying the full spectrum of traits exhibited by dolphins. He said: “It is vital researchers conduct further studies because not only will it lead to a better appreciation for species living within the depths of our oceans, it will lead to a better understanding of ourselves.”
Morton, F. B., Robinson, L. M., Brando, S., & Weiss, A. (2021). Personality structure in bottlenose dolphins (Tursiops truncatus). Journal of Comparative Psychology. Advance online publication. https://doi.org/10.1037/com0000259