All those PGA Tour players who have folded like limp dish rags while paired with Tiger Woods over the years will be a bit skeptical of the conclusions of this recent study (H/T to Tim Harford):

This paper uses the random assignment of playing partners in professional golf tournaments to test for peer effects in the workplace. We find no evidence that the ability of playing partners affects the performance of professional golfers, contrary to recent evidence on peer effects in the workplace from laboratory experiments, grocery scanners, and soft-fruit pickers. . . . We offer several explanations for our contrasting findings: that workers seek to avoid responding to social incentives when financial incentives are strong; that there is heterogeneity in how susceptible individuals are to social effects and that those who are able to avoid them are more likely to advance to elite professional labor markets; and that workers learn with professional experience not to be affected by social forces.

In other words, PGA Tour pros do not generally suffer from peer effects. Except while playing with Tiger Woods, that is. ;^)