 The groups with which we happen to identify ourselves may be very large (as in the case in which one self-defines as Muslim or French), or as small as a friends’ group. Some general group identities may not involve specific norms, but there are many cases in which group identification and social norms are inextricably connected. In that case group-members believe that certain patterns of behavior are unique to them, and use their distinctive norms to define group membership. Many close-knit groups (such as the Amish or the Hasidic Jews) enforce norms of separation proscribing marriage with outsiders, as well as specific dress codes and a host of other prescriptive and proscriptive norms. There, once an individual perceives herself as a group-member, she will adhere to the group prototype and behave in accordance with it. Hogg and Turner (1987) have called the process through which individuals come to conform to group norms “referent informational influence”.