Fig. 2.

The camaraderie effect may have evolved as a by-product, or a spandrel, of two adaptive psychological capacities, social reward and empathy. Social reward supports a motivation for living in groups and is responsive to aggressive and affiliative social cues. The affective states included in social motivation include isolation aversion and social reward. Social reward and isolation aversion are two of four affective states that can be inferred from social CPP testing. Other states include social aversion and isolation reward and may play a role in voluntary dispersal. The survival value of social reward is that it supports group living. Empathy is useful for predicting future events from social cues, such as the presence or absence of a threat in the environment from cues of calm or fear. In turn empathy engenders an affective state of vicarious calm or vicarious fear, so one can be alert to dangers not perceived directly or one can be calm under situations felt to be safe by others. In combination, social reward and empathy can generate the camaraderie effect, a process whereby vicarious feelings of others toward the actor can be either discomforting or can engender a sense of well-being. In turn, these psychological states may affect physiological health. These ideas are presented as text over a photograph of a spandrel in San Marco Cathedral, showing social reward and empathy as adaptive psychological states, represented by the arches holding up the dome with the camaraderie effect as a spandrel between these functional and highly adaptive arches