Your Most Helpful Colleague (Don't You Hate Him?)

From HBR blog. Wouldn't any group cherish a member who went above and beyond? It would seem self-evident that someone who behaved selflessly and in the interests of collective achievement would be a boon to the group's performance and happiness. Indeed, the Nobel laureate Herbert Simon argued in 1979 that such people are necessary in groups, if for no other reason than to give more self-oriented members someone to exploit. Consider the alternative, too: In a group consisting mainly of self-oriented people, the collective effort doesn't add up to much, and many tasks either go undone, or are done insufficiently.
Research suggests, however, that such selfless contributors are not so valued by their colleagues. In fact, they can inspire such negative reactions that others might believe the group would be better off without them. In a series of studies Asako Stone and I conducted, we found this to be the case: selfless people were almost as unpopular as their polar opposites, the very greedy people who contribute next to nothing but expect to reap the full reward of a group's success.