Differentiation of Self is a core concept in Bowen Family Systems Theory. Bowen borrowed the concept of differentiation from cell biology. All cells start out presumably as stem cells. As cells mature they specialize in different types of cells. These specialized cells perform different functions. Our bodies contain skin cells and blood cells and brain cells and many, many more different types of cells (did you know that there are about 250 different types of basic cells in the human body?!).
In Bowen Theory, self-differentiation means the ability to remain a self in relationship with other selves. A self-differentiated person is able to hold to their own values, beliefs, and principles while allowing others to disagree. A self-differentiated person maintains emotional connection with others while not necessarily agreeing with another’s opinions, actions, or values.
Self-differentiation can be difficult to achieve because of togetherness forces. Togetherness forces create the desire to be like others, to agree on values, beliefs, principles, and feelings. Togetherness pressure causes groups to bond and maintain their bonds. Extreme togetherness pressure can result in emotional fusion. Fusion can happen in many types of relationships. Spouses can be emotionally fused. A parent and a child can emotionally fuse. Siblings can fuse emotionally. In relational fusion, we cannot distinguish one person from the other person.
We learn the basic skills of self-differentiation as we mature from child to adult. Bowen theorized that we achieve our basic level of self-differentiation in our families of origin. Most people function at a fairly low level of self-differentiation. Bowen himself estimated that on his very best days, he functioned at about 60-75 on a scale of 100 (100 being an entirely self-differentiated person). Thus, gaining in differentiation of self is a lifetime journey. We need mentors and coaches to help us along the journey of learning and growing.