Generally, a person is identified as body-based, heart-based or head-based depending on their enneatype and which center that enneatype is in. Are we just body, heart or head or are we all three? The answer seems obvious to me.

Oscar Ichazo's trifix addresses this in a way. Here's a quote from the Advanced Fixations and Autodiagnosis^sm training description at Arica.org.

Each individual has three Fixations, which correspond to the three Instincts as proposed in the Protoanalytical theory. One Fixation is the major or predominant Ego-entity and the other two Fixations are the Minor Fixations or Co-egos.

Although the Arica system is not the same as the enneatype system, it does allude to a more wholistic approach when looking at an individual. The trifix emphasizes the three instincts and not the the three centers. Here are the three instincts as described at the Arica.org website.

The Conservation Instinct is the instinct for self-preservation and corresponds to our relationship with our mother and our digestive system.

The Relation Instinct is the instinct for relating with others and is connected to our relationship with our father and our circulatory and respiratory systems.

The Adaptation Instinct is the instinct with which we adapt to our surroundings and environment and is associated with our relationships with our siblings and children and our central nervous system.

The instincts of the Arica system are similar to yet different from the instincts of the enneatype system. Ichazo's trifix seems to have been reinterpreted in the enneatype system as representing the three centers instead of the three instincts. This difference was brought to light recently and the enneatype version of the trifix was renamed tritype.

The tritype approach assumes each individual has one type in each center. So for example, a type 1w9 may have a trifix of 1-2-6 (1 in the body-based center, 2 from the heart-based center, 6 from the head-based center). Although I agree with the concept that we are all three centers, I don't agree with the trifix for the following reason: the trifix is based on the assumption that the placement of the enneatypes within the centers is correct. I won't go into it here, but types 3, 6 and 9 seem to be placed in the wrong centers.