Trading off pain/​effort while gripping for...well, whatever it was that made people want to grip the handgrip in the first place. The feeling of having been helpful in the study? Personal pride at believing yourself to have high willpower?
Trading off pain/​effort while gripping for...well, whatever it was that made people want to grip the handgrip in the first place. The feeling of having been helpful in the study? Personal pride at believing yourself to have high willpower?