What is the outgroup homogeneity effect? How does distinctiveness play into this effect?

What is the outgroup homogeneity effect? How does distinctiveness play into this effect?

As we talked about, we have a natural tendency to categorize people when we encounter them. When this is combined with a tendency to prefer the ingroups over outgroups, we get what is called the outgroup homogeneity effect. This is the perception that our own group members are more distinct from one another than members of other groups. This may be best illustrated in a statement "they all look alike". In fact one of the areas of research that I used to work on is on cross-race eyewitness identification. Essentially, because we perceive members of outgroups to be more similar, we are less able to identify those differences when we do encounter them. Thus, to us it may seem true, they all might appear to look alike.

Understanding of this effect is starting to make its way into mainstream pop culture. Check out this clip from The Good Wife.

On the other hand, we do see diversity within our own group. Why does this distinction occur? Why do we assume that all members of the outgroup are the same? Let us assume that we have less experience with outgroup members then ingroup members. Therefore outgroup members are going to be more distinctive. Distinctive people draw attention. For example being the only male in a group is distinctive. We use limited experience with member of a given group to guide impressions of the entire group (e.g., all people of African descent are good at basketball).