Question

Why does the skin of your finger shrink. When you wash your cloth for a long time.

Answer 1

actually there are different theories for it.
One such theory is evolution.It is that skin shrinks in water to increase our grip with wet hand. You can try this at home by --
1. Take marbles and dip in water
2 keep one dipped in water untill skin shrinks and other hand outside of water
3 try holding wet marbles with both hands one by one. You will notice wet hand with shrinked skin has high grip.

this prooves a theory that skin shrinks for grip due to evolution.

This is just a a theory. As i said earliet there is no specific reason for it. So i explained the widely accepted theory with simple activity.
Hope it helps ya !!

Answer 2

Because of exosmosis. The outside solutions of detergents acts as hypertonic solution for
the cells of our finger....
Thus, it results in shrinkage of or fingers during washing of clothes for a long time."