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Also when we don't know the properties of an object we are about to manipulate we'll approach it cautiously and learn it before we apply too much force. This tends to happen transparently and quickly for adults, but for infants you can watch it play out more slowly.

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My guess is that it helps a lot that we have flexible cushioned fingertips that are highly sensitive to pressure. That's a hardware feature that robots mostly lack.

Our evolution of nails, as opposed to the much more common claw, is another part of the symphony of touch. It provides a hard backstop to assist with touch sensitivity.

Imagine if the tip of your finger could just bend back. It would be way harder to know what you’re touching!

> Imagine if the tip of your finger could just bend back. It would be way harder to know what you’re touching!

I don’t think so. I have hitchhikers thumb, so my thumbs do bend backwards. They don’t feel disadvantaged in terms of touching compared to my other fingers.

I’m talking about just the tip, the part you use primarily for touch, not the whole finger segment. You’d need to be missing a nail - and if you ever are missing one, you’ll be surprised how much of your sense you lose!

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