Why does getting your fingers wet help open plastic bags

Question

Why does getting your fingers wet help in opening the plastic fruit and vegetable bags from the roll at the grocery store. It seems like wetting them makes your fingers stick to the bag yet, water normally makes things more slippery.

In: 1

Answer 1

The evolutionary purpose of fingerprints is not to help catch criminals. They serve to increase friction when the fingertips are wet. Water makes smooth things slippery, but fingerprints evolved to counteract this specific property of water.