Categories are characterized by a collection of individuals who are similar in some way. Categories become groups when their similarities have social implications. For example, when people treat others differently because of their race, this creates groups of different races. For this reason, categories can appear to be higher in entitativity and essentialism than primary, social, and collective groups. Entitativity is defined by Campbell as the extent to which collections of individuals are perceived to be a group. The degree of entitativity that a group has is influenced by whether a collection of individuals experience the same fate, display similarities, and are close in proximity. If individuals believe that a group is high in entitativity, then they are likely to believe that the group has unchanging characteristics that are essential to the group, known as essentialism. Examples of categories are New Yorkers, gamblers, and women.