Perceived risk differences occur depending on how far or close a compared target is to an individual making a risk estimate. The greater the perceived distance between the self and the comparison target, the greater the perceived difference in risk. When one brings the comparison target closer to the individual, risk estimates appear closer together than if the comparison target was someone more distant to the participant. There is support for perceived social distance in determining the optimistic bias. Through looking at comparisons of personal and target risk between the in-group level contributes to more perceived similarities than when individuals think about outer-group comparisons which lead to greater perceived differences. In one study, researchers manipulated the social context of the comparison group, where participants made judgements for two different comparison targets: the typical student at their university and a typical student at another university. Their findings showed that not only did people work with the closer comparison first, but also had closer ratings to themselves than the "more different" group.