Planet of the Apes: Chimpanzees Show Similar Personality Traits to Humans

Researchers at Georgia State University discovered that chimpanzees show similar personality traits to humans, though the traits vary according to the chimpanzees' biological sex.

"Our work also demonstrates the promise of using chimpanzee models to investigate the neurobiology of personality processes," Georgia State psychology professor Robert Latzman, who led the research team, said in a news release. "We know that these processes are associated with a variety of emotional health outcomes. We're excited to continue investigating these links."

To assess this resemblance, chimp caregivers filled out a Chimpanzee Personality Questionnaire and rated individual chimps - from the Yerkes National Primate Center at Emory University - in 43 categories based on the animals' observed daily behavior.

The analysis showed that the most fundamental personality trait for chimpanzees is dominance - deemed as "Alpha" - compared to a more playful and sociable "Beta" chimp.

But we well know that human's personality traits are more complex than just "Alpha" or "Beta" categories, so researchers broke them down even further. Alpha personalities statistically break down into tendencies toward dominance and disinhibition while Beta personalities show low dominance and positive emotionality.

Furthermore, the five personality traits conscientiousness, dominance, extraversion, agreeableness and intellect statistically stem from the aforementioned, more rudimentary traits. These five traits equate to those found in humans.

This research shows a neurobiological basis for personality as well. Chimps who were born with a gene variant that controls the hormone vasopressin behaved differently than their peers: males demonstrated more dominance and disinhibition and females less of both.

The findings show that these personality traits have also developed from an evolutionary standpoint. The neurobiological bases of personality can vary according to the biological sex of the chimpanzee. What's more, chimps and humans have the same ingredients than comprise each one's personality, seemingly due to the fact that both species have similar neurobiology.

"These results are particularly significant in light of the striking parallels between the major dimensions of personality found between chimpanzees and humans," concluded Sam Gosling, an internationally known researcher in cross-species personality research.