In everyday social exchanges, being mean to people has a lot more impact than being nice, University of Chicago researchers suggest.

Lead author Boaz Keysar said feeling slighted can have a bigger difference on how a person responds than being the recipient of perceived generosity -- even if the net value of the social transaction is the same.

http://www.upi.com/Health_News/2008/12/23/Being_mean_bigger_deal_than_being_nice/UPI-19611230012454/