If It Pays To Be a Jerk, Why Isn’t Everyone That Way? Unraveling the Evolutionary Puzzle

Rude Angry Man Shouting

A research study found that male chimpanzees with bullying, greedy, and irritable personalities achieved higher social status and had greater reproductive success than their more submissive and conscientious counterparts. Researchers from the University of Edinburgh and Duke University observed 28 male chimps in Tanzania’s Gombe National Park to determine the impact of personality traits on success. While the benefits of aggressive behavior were clear, the team found no evidence that certain traits were only advantageous at specific life stages, leading them to conclude that other factors, such as environmental or social conditions, may explain the diversity of personalities in chimpanzees.

Long-term research on chimpanzees offers new clues to the puzzle of personality.

A recent study reveals that male chimpanzees with aggressive, bullying personalities attain higher social status and greater reproductive success. Researchers believe that factors like environmental or social conditions might explain the diverse range of personalities observed in chimps.

Throw a tantrum. Threaten, shove aside, or steal from your colleagues. Science confirms, yet again, that brutish behavior can be an effective path to power. And not just in humans, but in chimpanzees, too.

A new study published on April 24 in the journal PeerJ Life and Environment found that male chimps with more bullying, greedy and irritable personalities reached higher rungs of the social ladder and were more successful at siring offspring than their more deferential and conscientious counterparts.

But if that’s the case, researchers ask, why isn’t every chimp a bully?

A research team led by scientists at the University of Edinburgh and Duke University followed 28 male chimps living in Gombe National Park in Tanzania.

Frodo the Chimpanzee

Known as a bully, Frodo the chimpanzee was Gombe’s alpha male for five years. Credi: Ian C. Gilby, Arizona State University

A previous study of Gombe chimpanzees led by Edinburgh’s Alexander Weiss along with Duke professor Anne Pusey and colleagues showed how some chimpanzees are more sociable, while others are loners. Some lean towards easy-going, while others are more overbearing or quick to pick fights.

Tanzanian field researchers who knew the chimpanzees well performed the personality assessments, based on years of near-daily observations of how each chimpanzee behaved and interacted with other chimps.

In the current study, researchers found that male chimps with certain personality traits — in this case, a combination of high dominance and low conscientiousness — tend to fare better in life than others.

“Personality matters,” said Joseph Feldblum, assistant research professor of evolutionary anthropology at Duke and the other lead author of the study.

It may not be shocking to learn that bullying has its perks. But for some researchers, findings like these pose a conundrum: If males with certain personality tendencies are more likely to rise to the top and reproduce, and pass the genes for those traits on to their offspring, then shouldn’t every male be that way?

In other words, why do personality differences exist at all?

“It’s an evolutionary puzzle,” Feldblum said.

One long-held theory is that different personality traits pay off at different points in animals’ lives. Even if being aggressive gives young male chimps an edge, it might backfire when they’re older. Or perhaps certain traits are a liability in youth but an asset in old age.

“Think of the personality traits that lead some people to peak in high school versus later in life,” Weiss said. “It’s a trade-off.”

But when the team tested this idea, using 37 years of data going back to some of Jane Goodall’s early work at Gombe in the 1970s, they found the same personality traits were linked to high rank and reproductive success across the lifespan.

The findings suggest that something else must explain the diversity of personalities in chimpanzees. It might be that the “best” personality to have varies depending on environmental or social conditions, or that a trait that is beneficial to males is costly to females, Feldblum said.

If that were true, then “genes associated with those traits would be kept in the population,” Weiss said.

Not too many years ago, the mere suggestion that animals have personalities at all was considered taboo. Jane Goodall herself was accused of anthropomorphism when she described some of the Gombe chimpanzees as “bolder” or “more fearful” than others, some as “affectionate” and others “cold.”

Since that time, scientists studying creatures ranging from birds to squid have found evidence of distinctive personalities in animals: quirks and idiosyncrasies and ways of relating to the world that remain reasonably stable over time and across situations.

Weiss says personality ratings for animals have proven to be as consistent from one observer to the next as are similar measures of human personality.

“The data just don’t support the skepticism,” Weiss said.

Reference: “Personality traits, rank attainment, and siring success throughout the lives of male chimpanzees of Gombe National Park” by Alexander Weiss, Joseph T. Feldblum, Drew M. Altschul, D. Anthony Collins, Shadrack Kamenya, Deus Mjungu, Steffen Foerster, Ian C. Gilby, Michael L. Wilson and Anne E. Pusey, 24 April 2023, PeerJ Life and Environment.
DOI: 10.7717/peerj.15083

This research was supported by grants from the National Science Foundation (#BCS-9021946, #BCS-0452315, #BCS-0648481, #BCS-9319909, #IIS-0431141, #IOS-1052693, #IOS-1457260, #EF-0905606 and #DGE-1106401), the Carnegie Trust for the Universities of Scotland, the Jane Goodall Institute, the U.S. National Institutes of Health (R01-AI058715), Harris Steel Group, the University of Edinburgh, University of Minnesota, Duke University and the British Academy (PF20/100086).

11 Comments on "If It Pays To Be a Jerk, Why Isn’t Everyone That Way? Unraveling the Evolutionary Puzzle"

  1. FrequentFlyer | April 26, 2023 at 6:26 am | Reply

    Anyone that thinks animals dont have personalities is just speaking from ignorance.
    Hell even my goats have distinct personalities.
    They may not be the most complex personalities but still each one is unique.

    • True 100%
      Anyone who has grown up on a farm or has a house full of cats knows this.
      Western science is extremely ignorant and arrogant.

      • Torbjörn Larsson | November 29, 2023 at 11:06 pm | Reply

        Science is extremely useful and knowledgeable.

        Those who prefer anecdotes instead of facts are extremely ignorant and arrogant.

  2. Matthew H Iskra | April 26, 2023 at 11:49 am | Reply

    Huh. I recently watched a documentary on this. It boils down to four chimpanzees can hold the aggressive one down and kill him. Thus the lone jerk is balanced by the cooperative and better communicative chimpanzees. The documentary was about the fact that yes, other primates do engage in something like warfare.

  3. I don’t think you’re going to find out why humans are so obnoxious by watching chimps! Humans are supposed to be the apex intellect, with a conscience, and compassion, empathy, concern, love, worship, laws, government, amongst many other things.

    That really throws a lot of shade on humanity, if we feel we can learn about ourselves by watching chimps? Isn’t that a step backwards? It’s kind of like studying birds by watching houseflies, or maybe butterflies.

    • Yes and no. Chimps, being our closest living relatives, can actually infer much regarding things like our automation, intrinsic behavior, fight or flight responses, etc. The hierarchical structures within chimps and apes are incredibly similar to the group dynamics of humans.

      Also, there’re certain advantages with using such animals as study – the impossibility of the ‘blind study’ being compromised, for example. People are apt to catch on if they are studied for an extended amount of time, thus compromising the study. It’s often a simplified microcosm into our own dynamics and behaviors.

      Lastly, generally speaking, your average person has those traits you mentioned. However, not all. There does indeed exist psychopathic gadflies, if you will. People literally void of empathy, those with absolutely no acquiescence to the expectations of government and society, etc. This is not your average human, to be sure. But they are far from unheard of. None of the conclusions drawn from such studies are considered hard science (none of these anthropological, or even psychological disciplines are), but it’s still quite revealing.

    • Torbjörn Larsson | November 29, 2023 at 11:13 pm | Reply

      Humans are not “supposed” to be anything, especially not apex – that is a human deceit.

      No, studying our sister lineage for differences with more distant apes such as gorillas are informing of shared traits and constitute a step forward. Of the biological traits chimps share with us conscience, and compassion, empathy, concern, and arguably love (such as a mother’s love for her child). The rest is human specific culture – arguably worship is not its apex but its Bronze Age butt end – and hence is not the topic of these studies.

  4. Sunny, western science isn’t either extremely ignorant or arrogant. No one is disputing the psychological variability easily observed in animals but problems arise when human derived labels are applied to non-humans. Terms for human characteristics are very unlike to map satisfactorily onto a different species.

    • It’s all we have as a reference.
      If we speak beyond our experience to compare, we are speaking nonsense. Humans use human references.
      Now we are all from the same planet, so emotions are emotions; human, do, cat, chimp, etc. PERCEPTION within is the thing we have no reference for because how you would perceive something and how I would perceive something already is two different things.
      Seeing things just as they are experientially and not conceptually is what is beyond western science and what I was referring to.

      • Torbjörn Larsson | November 29, 2023 at 11:18 pm | Reply

        We can all agree that science is global, not “western” (though its roots were), and useful for such things as making ScieTechDaily.

        Moving on from science and usefulness, differences in experiences are not facts, its factless anecdote of no value except for the individual. It is, to loan your term, speaking nonsense when the discussion is about science.

  5. Altruism is preferred option but only when a persons X conditions are met. Otherwise situations will baseline into an estimation of perceived benefit scenario from one or more parties measured against maslow’s hierarchy of needs. Situations are not static and constantly being reassessed.

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