There is a good reason for Ulla Zang's personality test having nine different designs and personalities. Psychologists have determined that there are nine basic personality types. Although there are these nine basic types, everyone is still different and no personality can be defined as exactly one of these nine types. One of these types, however, is usually dominant in every person. These nine types are commonly arranged in a shape called an enneagram.

[ http://www.enneagraminstitute.com/images/E-TypesNumber.gif ]

This shape shows the nine basic personality types and how they relate to eachother. There are many different relationships between all the types. Ulla Zang's personality test builds on the nine basic personality types by associating each one with a particular design consisting of shapes and colors.

Some of the relationships shown in the enneagram are also expressed in Ulla Zang's personality test. One example is the association of the three triads of the enneagram (“thinking”, “feeling”, and “instinctive”) to the shapes presented in each design. For example, the designs for the "thinkers" are more square than the designs for the "feelers" which tend to be more rounded.