The Enneagram is a personality typology stating that there are nine basic types of personality, each represented by a different number from one to nine. According to Riso (1987), in addition to being one basic type, people also have a wing of (i.e. possess traits of) one of the two
types represented by a number adjacent to that representing the basic type. If Riso's argument is correct, people presented with brief descriptions of the nine types should perceive maximal similarity between types which are represented by adjacent numbers. This hypothesis was examined
in the present study, but was not supported.