In real life, a tin foil hat protects from waves. In the block heads it stops the mind control.
I put tin foil over my phone and it lost connection.
I put a tin foil hat on my block head, and it seemed to loose connection of me, doing its own thing.
Know I put a tin foil hat on all 3 of my block heads, leaving the last 2 to meditate.
My block head strangely enough started to mine dirt, and all 4 others mined the same one, using their bare hands rather then the tin spade.
My advice: Do not craft a tin foil hat as its a waste of tin and a waste of foil and your block head goes crazy. NUFF SAID.
Also the tin foil hat makes block heads in love with sharks.