Chimpanzees seem to have a reputation for having super-strength when compared to humans of similar size, but now a study is considering whether these claims are true and if any better explanations can be deduced from taking a closer look.
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The study, which has been published in the Proceedings of the National Academy of Sciences, reveals that many these stories about chimpanzees’ super strength are most likely anecdotal.
By taking a closer look at chimpanzees’ muscle fibers, researchers saw only marginal improvements in power output when compared with comparable human muscle fibers.
Instead of being twice as strong or several times stronger, as many chimpanzee stories might have you believe, the researchers found that chimpanzee muscle fibers could only output approximately 1.35 times more power than comparably-sized human muscle fibers.
Notably, this difference wasn’t due to having superior muscle fibers either; instead, it was because chimpanzees simply had a higher diversity of muscle fibers than humans did, which marginally adds to their overall strength for better or for worse.
When it comes to muscle fibers, there are generally two different kinds: fast-twitch and slow-twitch. The former is responsible for short-term strength, while the latter is responsible for long-term endurance. Different mixtures of these fibers yield different strengths and endurances, each of which have their own unique purposes.
Chimpanzees seem to have some more short-twitch fibers than humans do, but testing revealed that their muscle fiber construction was overall consistent with most mammals, and so there was no reason to believe that the creatures were several folds stronger than humans. On the contrary, humans have more slow-twitch muscle fibers, which indicates that while chimpanzees are slightly stronger, humans are slightly more endurant.
Although 1.35 times is still considered “stronger,” it’s by a very small amount, and the data seems to discredit the many horror stories that have popped up over the past century that depict chimpanzees as having super-strength compared to humans.
“Contrary to some long-standing hypotheses, evolution has not altered the basic force, velocity or power-producing capabilities of skeletal muscle cells to induce the marked differences between chimpanzees and humans in walking, running, climbing and throwing capabilities,” the researchers note in their study.
“This is a significant, but previously untested assumption. Instead, natural selection appears to have altered more global characteristics of muscle tissue, such as muscle fiber type distributions and muscle fiber lengths.”
Now when you hear someone saying that chimpanzees can lift cars off the ground, you can refer them to this study and say they might be exaggerating just a little bit.
