The gripping hand

A somewhat interesting article at Nautilus about how much we should (or shouldn't) read into studies showing that grip strength is weakening pretty rapidly in us modern humans.   (Well, Americans in particular.)

I liked this bit of history:

Pound per pound, babies are remarkably strong. The parent learns this the first time they proffer their finger. In a famous series of experiments in the late 19th century—of the sort one can scarcely imagine today—Louis Robinson, a surgeon at a children’s hospital in England, tested some 60 infants—many within an hour of birth—by having them hang from a suspended “walking stick.” With only two exceptions, according to one report, the infants were able to hang on, sustaining “the weight of their body for at least ten seconds.”⁹ Many could do it for upward of a minute.  In a later-published photograph, Robinson swapped out the bar for a tree branch, to bring home his whole point: Our “arboreal ancestry.”

Going back further:

As the evolutionary biologist Mary Marzke argues, our hands today were literally shaped around millions of years of using and making tools (our cerebral hemispheres, notes John Napier, author of the classic study Hands, expanded as our tool making did). The human hand became an almost perfect gripping machine. That long opposable thumb, enabling what has been termed the “power grip” and the “precision grip,” looms most obvious. But consider also the Papillary ridges, those tougher, thicker parts of the skin, found on the human heel, but also on the human palm—a vestigial souvenir from our time as quadrupeds. Their placement, as Napier writes in Hands, “corresponds with the principal areas of gripping and weight bearing, where they serve very much the same function as the treads on an automobile tire.” Eccrine glands perfectly line the papillary ridge, Napier notes, providing a grip-enhancing “lubrication system.” This sort of “frictional adaptation” does not kick in until we are around 2, writes Frank Wilson in The Hand (before then, we just grip harder).

Gripping, then, is a deep part of our biology and evolution as a species. It’s also part of a long story in which we have been getting weaker for millions of years, largely because of a decline in physical activity. The human skeleton, for example, is “relatively gracile” (weak) compared to hominoids.¹² Those infants tested by Robinson, stout hangers-on though they may have been, can hardly compete with infant monkeys, who can hang on for upward of a half hour. Why? Because they need to. “Modern infants,” as one researcher notes, “as well as their fairly recent human antecedents, do not need to hang on with their hands and feet from the moment of birth.”¹³

I would have guessed that men not sexually partnering much in countries like Japan or China might have activity which compensates for gripping strength loss from automation, if you get my drift.   But perhaps I am wrong...