Sep 14
Once more, I prefer my title - "This time, take the fifth" - to the one the
folks at Mint gave ("The untold story of the little finger"). But never
mind.
This column is about the utility (or otherwise) of that fifth finger you
have on each of your hands. The smallest, the thinnest, apparently the
weakest. So maybe apparently useless? Well no, it has its uses. But more
than that, there are scientists who have investigated the evolution of the
fifth, and found it was particularly useful in crafting those prehistoric
stone tools - hand-axes, I've seen them called - we're all familiar with.
How do they know this? Amazingly, because there are people even today who
craft in the same way.
Take a look:
https://www.livemint.com/opinion/columns/the-untold-story-of-the-little-finger-11693506049578.html
And tell me about the titles.
cheers,
dilip
---
This time, take the fifth
Reading about tennis not long ago, I found this interesting tip for
improving your serve: don't grip the racquet too hard. In fact, let your
fourth and fifth fingers essentially hang free. Grip the racket only with
the thumb, the second and third fingers.
Whoever offered this friendly advice also observed that the great Pete
Sampras gripped his racquet that way. Seemed like a reasonable example to
emulate, so I tried this. I can't claim that I served well as a result. But
I can claim that I served better - I was able to impart to the ball a
little more power, direct it a little more accurately.
Pity is, I have since slacked off on playing regularly, so I don't know if
these improvements will still feature if and when I get back to the court.
But it did get me thinking about matters outside tennis. About my fifth
finger, in particular. If it is essentially dispensable in this matter of a
tennis grip, does it serve any real purpose at all? You may scoff at my
extrapolation from tennis to life itself, but I did wonder. As I write
this, for example, I'm raising my glass of gin and orange juice using only
thumb and the next two fingers. No fourth, no fifth. My glasses? Thumb and
index. Lifting a suitcase? All five, but I could do it without the little
finger.
In short, the examples abound, of life without the fifth. No doubt it makes
certain things easier, but it's easy to see it as an appendage we don't
strictly need. Which of course raises the question: why is it there? Why
haven't we evolved to rid ourselves of that finger?
The simple answer to those questions is that I'm taking far too simple a
view of the little finger. Perhaps because our thumb is such a unique,
distinctive limb, it has been studied far more intensively than the other
four fingers, especially the fifth. In fact, there are scientists who have
noted that the analysis of the fourth and fifth fingers have often been
"limited to examining their length relative to the first digit."
Yet tennis and gin grips aside, the fifth is stronger than you might
imagine and has many uses. In fact, there's evidence that in certain human
activities, it is used more often, more heavily, than the thumb and
forefinger.
Given that, think about this sentence for a moment: "The fifth digit
therefore appears key to [over] 2 million years of [certain] activities, a
behaviour that likely contributed to [its observed] anatomy."
And what were these activities that shaped our little fingers over all that
time?
According to the paper where I found all the quotes above ("The unexpected
importance of the fifth digit during stone tool production", Alastair JM
Key et al, Nature, 13 November 2019), it's the production of stone tools.
Ancient stone tools were made of flint, primarily because it's a stone that
is easy to shape, yet maintains a sharp edge and is hard enough to cut or
strike with. The tools are produced by a process known as "knapping", used
even today to shape flint. A knapper will typically hold a large chunk of
flint in one hand, brace it against her thigh, and bring her knapping
instrument down sharply on the edge of the flint. If she's done it right, a
flake breaks off the chunk. It has sharp edges, which means it can itself
become an arrowhead, or the point on a spear. Meanwhile, the knapper will
probably want to keep on hitting the chunk of flint, breaking off still
more flakes. Maybe you have a picture in your mind of how the chunk gets
shaped in this way, eventually resembling a teardrop with a sharp point and
edges. This is your regulation Stone Age hand-axe.
Note that the knapper used both her hands for this job. One, to hold the
chunk of flint. The second, to grip the knapping instrument. Relevant to
this discussion, she used the fifth finger on both hands.
If you think about it - better yet, imagine yourself doing the knapping -
you'll know how this works. Try holding a fist-sized object without using
your little finger. You'll quickly realize that you don't really have a
reliable grip on it; sometimes you might even put that finger under the
object to support it. But even if you don't do that, you can feel the
pressure the fifth finger exerts as part of your grip. In short, that
finger plays an important role in supporting it, especially if it is going
to be hit with a knapping instrument.
The same applies to the knapping instrument. Take hold of a relatively
thick rod about six inches long. Now imagine using that to strike a stone
you have in your other hand. Even in the picture that's in your mind, I'm
certain your little finger is holding the rod tight. Again, try holding it
without using that finger. It just doesn't feel like you are holding it
firmly enough to be able to deliver a strong blow to the chunk of flint.
In the paper I mentioned above, the authors turn these thought experiments
into reality. They observed several "skilled flintknappers during multiple
stone tool production procedures." They recorded which of their fingers
exerted how much pressure on the objects in their hands. They found what
they refer to as a "heavy recruitment of the fifth finger" in these tasks,
and a "substantial loading" on it in comparison to the second and third
fingers. That is, the fifth finger played an important role, even more so
than the index finger and its neighbour, the longest of the five.
So once our human ancestors started making stone tools, about 2.6 million
years ago, the fifth finger "could have experienced selective
[evolutionary] pressure in response to these high demands" that were made
on it.
Yet remember that this is only to do with this tool-crafting exercise. Does
that fully explain why the fifth finger has evolved into the deceptively
strong, flexible and versatile digit that it actually is today? Were there
other influences on the evolution of our hands, and the little finger in
particular? After all, our prehistoric ancestors did plenty of other things
with their hands too. Three examples are feeding themselves, grooming
themselves and others, and using spears to hunt.
Probably not playing tennis, though.
--
My book with Joy Ma: "The Deoliwallahs"
Twitter: @DeathEndsFun
Death Ends Fun: http://dcubed.blogspot.com
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