The 5 most characteristic psychological personality traits of women and man are described in the specialized literature as the OCEAN model:

openness to experience (inventive/curious versus consistent/cautious)

conscientiousness (efficient/organized versus extravagant/careless)

extraversion (outgoing/energetic versus solitary/reserved)

agreeableness (friendly/compassionate versus critical/rational)

neuroticism (sensitive/nervous versus resilient/confident)

The model is a grouping of psychological personality traits developed from the 1980s based on statistics of survey data in the general population. The statistical model is called factor analysis and it shows associations of words that people use in daily language to describe aspects of personality, temperament and psyche in the same person. A conscientious person is more likely to be “prepared” than “messy”. Extraversion is associated with gregariousness, assertiveness, warmth, activity, and positive emotions. For every individual, the personality traits are on a continuum of a spectrum rather than present or absent. Varying shades of grey or brown as opposed to black, white, red or yellow.

Studies and research of various types, including in twins, have shown that approximately half of the variation between people is genetic and half is due to upbringing and environment. They are relatively stable from childhood through adult life in a great number of psychological and social science studies, carried out in different cultural and social environments.

In order to investigate whether personality traits are inheritted or aquired, people have investigated dolphins, who have developed a number of similar personality traits to humans. A study in the Journal of Comparative Psychology looked at dolphins from eight facilities across the world. Each dolphin’s personality was assessed by local staff.

The results of the study found a convergence of certain personality traits, especially curiosity and sociability. These similarities were found despite dolphins having evolved in a completely different environment from primates, with the last common ancestor living about 95million  years ago. Dr Blake Morton, a psychology lecturer at the University of Hull, 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.” He 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 curious.” Morton said that the Big Five, the most widely accepted model of human personality is defined by five traits, is supported by the dolphin study. “Scientists still do not fully understand why our behaviour comes down to those five traits, so one way of doing that is to compare ourselves to other animals – what we share in common and why,” he said. “I don’t want people to misinterpret that and say humans and dolphins have the same personality traits – they don’t. It’s just that some of them are similar,” he added.The study began in 2012, in countries Mexico, France, the US, the Bahamas and the Cayman Islands.

Personality structure in bottlenose dolphins (Tursiops truncatus). F Blake Morton, Lauren M Robinson, Sabrina Brando, Alexander Weiss. J Comp Psychol. 2021 Jan 18. doi: 10.1037/com0000259.

Comparative studies help identify why species are different. Bottlenose dolphins resemble primate species in several behavioral and cognitive traits. For example, like chimpanzees, dolphins live in fission-fusion societies, use tools, and have relatively large brains. The study examined 134 bottlenose dolphins, and found four personality domains. Openness, Sociability and Disagreeableness resembled personality domains of nonhuman primates. Directedness, a blend of high Conscientiousness and low Neuroticism, was unique to dolphins. Unlike other species, but like humans, dolphins did not have a strong Dominance domain. The overlap in personality structure between dolphins and other species suggests that selective pressures related to group structure, terrestrial lifestyles, morphology, social learning or tool use are not necessary for particular domains to evolve within a species. These psychological personality traits are obviously inheritted from an early stage of species development. They are embedded in the primate brains.

Dr Paulo Bittencourt

Compartilhe este artigo: