In Enneagram terms, your “wing” is the type—adjacent to your primary type—that flavors the your type’s expression. For example: if you are a Nine, your wing would either be Eight or One. If you have an Eight wing, the nomenclature is “Nine with an Eight wing.” If you spend any time on Enneagram-related discussion boards, you might see abbreviations like 9w8 or 9w/8 which are referring to the same thing.
What this means in practical terms is that while you remain your primary type, you will be influenced by your wing. As a Nine, your primary motivations will revolve around keeping the peace, focusing on the positive, and going along to get along. However, you will be influenced by your Eight wing, particularly in the way you express anger. Eights are prone to territorial anger that comes on strong and fast and can be over as quickly as it began. Nines with Eight wings are slow to anger, but once they are, it’s quick and decisive. In contrast, Nines with One wings express anger as a slow burn with a very definite focus on an internalized system of morality—much like Ones do.
Each of the nine types will be influenced by one or the other wing, leading to 18 subtypes. Looking at the Enneagram symbol, you will notice an arc between each point representing the types. This arc can be used as an expression of one’s wing such that the closer to the midpoint of the arc between two types, the stronger the wing will be. The closer to the primary type, the weaker the wing. Theoretically speaking, one could potentially land exactly on the primary type which would lead to “balanced wings,” meaning you’re equally influenced by both wings. However, this would necessarily be statistically rare.
One thing we always need to keep in mind is that we all have access to each of the types. It’s just that when we’re unconscious or behaving on autopilot, we tend to favor our primary type as influenced by our wing. As we become healthier, we begin to have greater access to the abandoned or neglected aspects of ourselves which we could say are expressions of the other types within us.
This greater access usually begins with the types that we have the strongest connections with, such as our “other wing,” our points of integration and disintegration, etc. I think that it’s due to this dynamic that some people feel they have been able to “switch” wings. However, I remain skeptical of the idea that we have access to both wings no matter where we are on the Levels of Development. This is simply because, by definition, our type and wing are expressions of Ego’s manifestation through us when we are less conscious, and the less conscious we are, the more rigid are our self-definitions and expressions of our type.