Personality characteristics of humans come from genetic roots and are further modified by the environment in the broadest sense, so as to optimize adaptability, survival, reproductive success, and longer lifespan. The same can also be assumed for others, especially closely related species. Humans do not show as strong a presence of a trait called dominance as their non-human relatives, where it leads to a hierarchically organized community; human society is much more egalitarian.
Comparative studies can identify and clarify some selective pressures that contributed to shared, or conversely different, characteristics in individual species. Although the bottlenose dolphin, Tursiops truncatus, has had its last common ancestor with primates 95 million years ago and has since lived in a completely different environment, some of its psychosocial and cognitive characteristics resemble those of non-human primates. Similar to chimpanzees, Pan troglodytes, they live in communities that gather and, under certain circumstances, split apart (fission and fusion), they have large brains, and they use tools.
An international team set out to explore some personality characteristics of dolphins. A total of 134 dolphins (56 males) aged 2–52 years (mean 16.8 ± 10.8 years) in 15 locations across eight different countries were observed. As a tool for assessing personality traits, the researchers used the Dolphin Personality Questionnaire, where on a five-point scale (1 = not characteristic at all to 5 = very characteristic), 49 items from a primate questionnaire were adopted. Each item was both defined and then explained in detail. For example, the descriptor "exhibitionistic, showy" was supplemented with the description "Acts as if deliberately trying to attract attention." The full questionnaire was administered to 85 dolphins, while the remaining dolphins were assessed with a shortened version of 42 items. In total, 82 raters participated in the study, yielding a total of 9,660 ratings with high agreement.
The results identified four major clusters of traits, of which three resemble characteristics found in primates and the fourth is entirely idiosyncratic, labelled "directedness", which is best matched by the term "directedness." It is marked by courage, decisiveness, precision, and speed, and its carriers lack shyness, timidity, clumsiness, submissiveness, indecision, and distractibility.
Openness similarly as in primates and in the Big Five in humans is characterized by the following traits: activity, energy, playfulness, creativity, inventiveness, curiosity, exhibitionism, excitability up to impulsivity, intelligence, and a complete absence of laziness.
Friendliness (sociability) is characterized by social intelligence, willingness to help, friendly attitudes, helpfulness, carefree-ness, flexibility, and on the other hand consistency, calmness, emotional balance, loving and warm attitudes, and lack of suspicion.
Disagreeableness is characterized by stubbornness, obstinacy, jealousy, aggression, independence, irritability, and dominance.
The personality complex itself that would indicate more pronounced dominance in dolphins is not present, just as in the Big Five we do not find signs of conscientiousness, but most importantly no signs of the negative trait in humans labeled neuroticism.
The authors conclude explicitly: Our study suggests that dolphin personality is similar to the personality of primates and other terrestrial species, including humans, with the exception that dolphins lack a domain of conscientiousness and a domain of neuroticism. The overlap of personality structure between dolphins and other species suggests that selective pressures such as those related to group structure, terrestrial life style, morphology, social learning, or tool use are not necessary for the development of certain characteristics.
Author: MUDr. Radkin Honzák psychiatrist
Morton, F. B., Robinson, L. M., Brando, S., & Weiss, A. (2021, January 18). Personality Structure in Bottlenose Dolphins (Tursiops truncatus). Journal of Comparative Psychology. Advance online publication. http://dx.doi.org/10.1037/com0000259