What is considered a real fist fight

Human evolution: did the human hand evolve for fistfight?

If you look closely at people and monkeys, you quickly notice how clearly we differ from our close relatives in the animal kingdom in terms of hand anatomy: while great apes such as orangutans or chimpanzees have long fingers and a short thumb our thumb is long, strong and particularly flexible in relation to the rest of the fingers. These features, according to the most common theory from science to date, have presumably established themselves in the course of evolution because they make us particularly skilled in handling and manufacturing tools.

But that could possibly only be half the story, argue at least David Carrier and his colleagues from the University of Utah. They believe that the shorter fingers and the longer, flexible thumb not only make our hand a precision tool - but that they were also developed so that especially the male representatives of our species can beat each other particularly well with their fists. Our special hand anatomy, Carrier argues, allows us, unlike monkeys, to clench a "supported fist" in which the thumb wraps around the index and middle fingers, which in turn press firmly against the palm. This finger position has the advantage that the metacarpal bones, which experience shows are most likely to be affected in fights, are better protected and therefore break less often.

In order to substantiate this theory experimentally, Carrier and his colleagues obtained eight arms from human corpses, clamped them in a pendulum-like device and then let them crash into a static target with various hand positions. At the same time, they measured how heavy the load on the metacarpal bones was from the impact. After hundreds of blows, the researchers finally came to the conclusion: With a clenched fist, at least the cadaver arms could strike with around 55 percent more force than a loosely closed fist without being damaged. Compared to the flat hand, it was even possible to hit twice as hard in this way under safe conditions.

No chance of breaking

The hand bones did not have a real chance of breaking in the experiment anyway: For technical reasons, the hands and fists only experienced a seventh of the strain that it takes on average to cause a fracture of the metacarpal bones. This is mainly due to the fact that the dead can no longer clench their hands into a fist and then open it again. In order to maneuver their test hands into the correct positions, Carrier and his colleagues therefore pulled the tendons of the forearm muscles and fixed them with a sophisticated construction made of fishing line and guitar head plates. If the fishing line was under too much tension, it would break during the experiment. The researchers therefore had to extrapolate the stress values ​​of a real strong blow, which, according to Carrier, is valid: the relationship between the force acting on the bones and how much they give way is therefore linear.

In the past, the scientist from the University of Utah let his fists fly several times in similar studies, essentially to prove that violence and aggression must once have played an important role in human evolution. In 2012, for example, Carrier showed in an experiment that you can hit harder with a fist than with the flat of your hand - at least if you put the appropriate force in relation to the impact area. A year earlier he had already come to the conclusion - also through a boxing experiment in the laboratory - that it is easier to distribute standing upright than on all fours and crouching. This gave him the idea that the upright walk of people could also have prevailed partly because men were better able to fight for women.

Controversial theory

However, Carrier's theory is highly controversial in research. Critics say, among other things, that there is hardly any historical or prehistoric evidence of extensive fistfighting among our ancestors. In addition, despite all evolution, the human fist is much too sensitive to be considered a serious weapon. It is much more likely that early humans were more likely to fight each other with sticks and stones. Carrier, however, vehemently opposes it: Even today, numerous assaults and disputes often and happily hit with the fist, as numerous studies have shown - and facial bones break much more often than hand bones.