Offerman, T. (2002). Hurting Hurts More Than Helping Helps European Economic Review, 46:1423--1437.

Previous experimental work suggests that both a dislike for an unequal division of payoffs and intentionality play a role to explain reciprocal behavior. This paper focuses on intentionality, and in particular on the question of whether negative intentionality matters more than positive intentionality. Experimental evidence obtained in the {\textquoteleft}hot response game{\textquoteright} suggests that this is the case: subjects are 67% more likely to reciprocate an intentional hurtful choice over an unintentional hurtful choice. Subjects are only 25% more likely to reciprocate an intentional helpful choice over an unintentional helpful choice. Additional evidence on the role of emotions helps explain this asymmetry between positive and negative intentionality. It is argued that a self-serving attributional style may be responsible for the observed phenomenon.