And once the nut is open, we are better at deftly pinch-gripping the meat. For all a chimpanzee’s impressive arm strength, he said, humans are much better at wielding a hammer to crack open a nut. Hopkins of the division of developmental and cognitive neuroscience at Yerkes National Primate Research Center in Atlanta. “That allows us to very strongly pinch an item, to a much greater degree than a chimp.”Ī strong pinch grip is at once powerful and precise, according to William D. Lycett, an anthropologist at the University of Kent in England. “Our thumbs are relatively long and our fingers relatively short compared to a gorilla or chimpanzee,” said Stephen J. Not by being opposable - apes and many monkeys have opposable thumbs - but by being exceptionally long, strong and flexible. You will not, however, be all thumbs, or even half thumbs, for as research into the evolution of the human hand has shown, the thumb is what sets apart our hands from those of other apes. To appreciate the centrality of manual anticipation to the seamless performance of tasks, try blocking the pre-cupping maneuver as you reach for a glass, and see how clueless you and your hand will feel about how to proceed. In groping for a pen, the thumb, index and middle fingers - the masters of fine-motor manipulations - form a preliminary pincer, while the ring finger and pinky (important for gripping bulkier objects, like bottles) tuck themselves politely under and out of the way. If we’re reaching for a water bottle, the hand takes on a generic open cupping shape, refining the curvature and angle of the gesture as the hand closes in on the bottle. Scientists have shown that our hands start assuming the necessary configuration as soon as the brain initiates an activity - if not a micromoment earlier. The brain also treats the hands as unified tools, often in ways of which we’re not consciously aware. Schieber said, “others to lift fingers back up and away from the key, others to hold them away.” “Some of the movement is to strike the key,” Dr. “But really, all the fingers are in motion all the time.”įor every keystroke, there’s a movement of every finger. The pianist playing Ravel or the typist clacking on Blogspot? “People tend to think, they’re hitting one key at a time, so they must be moving one finger at a time to hit that key,” Dr. Schieber, a professor of neurology and neurobiology at the University of Rochester Medical Center, “you’re really controlling your entire hand.” “Even when you think you’re moving just one finger,” said Marc H. Not only are the ring and pinky fingers physically tethered together by a shared tendon, as anatomists long have known measurements of neuromuscular activation patterns have shown that all fingers, including the ones with the greatest structural autonomy, the thumb and index finger, are keenly responsive to every flex and twitch of their neighboring digits. 2, a majority discover to their frustration that they just can’t curl the pinky palmward without the joints of the ring finger flexing along for the ride. The rare rubber joints notwithstanding, most people who attempt that first sequential digit-straightening exercise find that the thumb and index finger spring free of the fist with ease and that the middle and pinky fingers are not far behind, but that the ring finger is a stuck, stubborn mule: No matter how they struggle, it doesn’t want to move.īy a similar token in challenge No. What is the most important difference between a chimpanzee’s hands and our own? (a) the chimpanzee’s thumbs are not opposable (b) the chimpanzee’s thumbs are shorter than ours or (c) the chimpanzee’s thumbs are longer than ours. What does your hand start doing long before it makes contact with the desired object?Īnd a high-five to our nearest nonhuman kin: You’re at your desk and, without giving it much thought, you start reaching over for your water bottle, or your pen.
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