I was looking at the subject of violence, specifically physical violence in humans. The psychology of it is well documented. I wanted to know things from a different perspective though.

I was researching the physical attributes to such acts, not the emotional, psyche or social when I came across some research papers and blogs.

Did you know that only humans can make a fist - a true fist?

The human evolutionary road has given us a very good weapon for when those basal urges to smack the living daylights out of something comes to pass.

We evolved fists.

source Pxhere.com

The majority of ape type creatures have similarities, such as opposing thumbs, long fingers and so on. These are great for holding tree branches or smacking another monkey round the head with a rock. Humans however, have taken it a step further so we have precision dexterity. That aside, it also means that only humans can make a true fist. Only we can curl our fingers to the palm and lock over with a thumb so we have a ready made club to hand. (pun intended)

Why? Would we beat and shape a rock with it, or punch a mammoth? Not really. There's little use for a hand sized club other than to deliver a blow directly to source. That source would surely in reality only be another human or animal of similar size and weight-bearing.

Source

Even primitive man wouldn't be stupid enough to try and punch down a 1600 kg bear.

Prehistoric bear - Artist - funkmonk

Most of us already know that we humans evolved to have opposing thumbs so we could pick up a brick or thread a needle. I had not considered the defence factor being of any benefit other than we could make sharper points to our spears.

But a fist? That's a game changer. Now we have a formidable weapon on tap day or night so we could defend ourselves when there was nothing else to do but lash out.

I can only imagine that this became part of the 'steal a female' ritual or when tribesmen argued for hunting rites, or valuable space. The body chemistry of mating or survival would have been coursing through veins aeons before. As we evolved our hands for better dexterity, was the punch format a convenient side effect? Or did the two reasons run side by side? Did a man who found he had a strong, tightfisted punch survive better, win more battles and therefore reproduce more effectively?

Evolutionary biologists Michael H. Morgan and David R. Carrier at the University of Utah, who have suggested that while evolution was reshaping our hands to improve our ability to use tools, it was also shaping them to throw more effective punches. It wasn't by accident but as a direct result of the necessity to compete effectively at close quarters with fellow humans.
John Rennie

The fact that when a person makes a full fist locking with the thumb, a good, straight punch is not only extremely effective at causing damage where it lands, but it's effective in causing greater damage to the punched than to the puncher. The shape of the fist, the way the fingers curl, the locking thumb also means that the power resonating from contact is shock-waved back and dissipated more easily at the various joints along the hand and arm. A slap tends to power through the wrist more than anything. Strangling increases pressure on fingers and wrists. Only a punch can successfully knock out another person with minimal damage to the puncher.

BUT - is that true?

I have heard of fighters getting damaged hands and broken arms from punching. And why would boxers wear gloves if a hand punch was so effective? As a woman, I also know that a damned good slap, kick and scratch in the right places is far more effective.

In fact, there's recent research showing that hand injuries in elite boxing outweigh the facial, body and neurodegenerative injuries collectively despite the padded protecting gloves that boxers wear to save them from this kind of agony. Injuries such as wrist sprains and fractures, finger metacarpophalangeal joint extensor hood and capsule sprain (also known as boxer’s knuckle), various joint tears and bone breakages throughout the hand, wrist and lower arm were recorded.
see footnote for further reading.

Typical Xray of Boxer's Knuckle Injury and a "Normal" Hand Xray

Source

So if we evolved the shape of our hands primarily to use in attack or defence there wasn't a foolproof design applied. The simple act of bashing one's perfectly formed fist into an opponents jaw was at least as equally as likely to damage one's hand anyway ... and what could a good old prehistoric hunter do with a damaged hand?

But There's More

There is also an idea that in conjunction with the changing shape of our hands to elicit decent punches there could be a link to the changing shape of our faces too. According to some researchers the fact that we learned to throw a significant punch in our quest to be top dog could also have contributed to how our faces evolved to accommodate such violence thus reducing life threatening consequences

Researchers propose that human facial bones evolved to better protect against punches.

source

It seems, as usual in science, there is a counter argument; there is no correlation between facial feature development and the ability to smack one's opponent half way to next week. In fact my personal opinion is that evidence of such correlation is sketchy at the best. However, we should never dismiss just because we can't see an answer. It seems studies to prove and disprove the theory are continuing.

So was it a bilateral moment where two uses for one adaptation was a definite and intentional evolutionary strike forward? Or was the dexterity actually a secondary advantage once we grew our hands to the right shape? Maybe it was just coincidence that the ability to pick up and manipulate tiny objects enabled that primal violence to effective fisticuffs - A kind of happy accident...?

Further reading

human condition

Hand (N Y). 2017 Hand and Wrist Injuries in Elite Boxing
A Longitudinal Prospective Study (2005-2012) of the Great Britain Olympic Boxing Squad

Natgeo page on The Biggest Bear

Study - Face evolved to be punched

Further discussion - Face didn't evolve to be punched

Thank you to @mobbs for guidance to keeping this post withing Steemstem rules.