While the Enneagram symbol limits the number of different enneatypes to nine, a variety of enhancements have been introduced over the years to explain the differences within each type (i.e., why two people of the same type can present so differently). Some of the enhancements to the system are widely accepted and some are more author specific.

Here are some of the enhancements and the authors introducing them (as best I could determine).

• Instinctual Subtypes (Naranjo)
  • Instinctual Variants, Variant Stacking (?)
• Wings (?)
• Inner Lines
  • Stress Points (Palmer)
  • Direction of Integration (Riso)
• Levels of Development/Health (Riso)
• Trifix (Ichazo) or Tritype (Fauvre)

These enhancements explain that while an individual is and always will be only one of the nine enneatypes, certain other types or subtypes in the system have an additional influence upon or play a factor in their personality. 

These enhancements suggest to me that the nine enneatypes are insufficient in explaining personality. There are two approaches that can be taken when a system is insufficient: 1) enhance the system or 2) redevelop the system. With the enneatype system so dependent upon the Enneagram symbol, it seems the only choice taken has been to enhance the system by adding concepts to explain the limitations of the nine types.

Personally, I chose to go beyond the inappropriate use of the Enneagram symbol. However, doing so produces a new system for understanding personality and not simply an enhancement to the enneatypes. While that system is complete in my mind, I'm still clarifying the details in book form.

In the meantime, I'll try to explain and explore the pros and cons of the enhancements of the current enneatype system in future articles.