We study how an individuals effort choice is impacted by feedback on her own past performance and another individuals past performance. In an effort choice problem where effort is costly but increases the chance of receiving a prize, subjects who failed in the previous period increase their effort in the next period – behavior consistent with failure aversion. More interestingly, failed subjects who observe that their partner succeeded exert higher effort in the next period than failed subjects who observe that their partner also failed – behavior consistent with behindness aversion.