The human hand may have a pugnacious purpose, if a recent report by University of Utah researchers is to be believed. According to the study, the particular shape of the human fist makes it especially good at throwing punches, which might indicate that the human hand evolved specifically for fighting, reports Newsweek.
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“The human hand presents a biomechanical paradox. It is critical to most human behaviors: foraging for, preparing and ingesting food; crafting and using tools; building shelter; playing musical instruments; producing art; communicating complex intentions and emotions; and nurturing,” the researchers write in their study. “Yet, the hand is also our most important anatomical weapon, used as a club to threaten, beat and sometimes kill other humans.”
To test the punching prowess of the human hand, researchers designed a rather ghoulish experiment. They attached the arms of nine human corpses to a pendulum and swung them into dumbbells, attempting to simulate a punch. To keep the dead fists clenched, they tied them with fishing line. Several different positions were tested, but buttressed fists performed the best.
“A fully clenched fist does appear to provide significant protection to the metacarpal bones when the hand is used to strike,” wrote the researchers.
Although the researchers admitted that several factors likely contributed to the evolution of the human hand, they conclude that one of those factors — perhaps the principal one — was for fighting. They also suggest that sexual selection may have reinforced this trend, because females may have preferred men with greater boxing prowess.
It's a controversial conclusion, one that will require more evidence to prove than this experiment alone can provide. For instance, the fact that the human fist makes for an effective bludgeoning instrument could just as easily be incidental. Arguing that the human fist evolved to punch because it punches well is like arguing that pandas evolved to be furry because it makes them appear cuter.
A blogger at National Geographic has mocked the research, calling it “bro science.” Indeed, the researchers appear to have some preconceived notions about human nature, which may have informed their conclusions.
For instance, lead author on the study, David Carrier, told Discovery News: “Although some primatologists may argue that chimpanzees are the most aggressive apes, I think the evidence suggests that humans are substantially more violent.”
Carrier goes on to cite other ad hoc examples to support this view, suggesting that while chimps and humans are both known to rape and go to war with one another, humans do these things on a larger scale.
The problem is that even if Carrier is correct about humans being the most violent, it still doesn't mean that the human hand evolved for punching because it is effective at punching. It's all a rather odd, circular line of argument.
Of course, that doesn't mean that the study's evolutionary conclusion is wrong either. It just means that more evidence will be needed.