Self-centeredness
Selfishness, or caring more your one’s self than for other, actually damages the interests of everyone in a team – include those of the selfish person.
A team should function as a group working toward a common interest, but selfishness causes the team to splinter, as each individual strives toward what he sees as his interest. In this divided state, the “team” ceases to function as a cohesive unit, and little, if anything is accomplished.