If you want to have a peaceful, healthy, intimate relationship with your partner, there is one main thing you must concern yourself with: differentiation.

In developmental biology, differentiation is the process by which a less specialized cell develops or matures to become more distinct in form and function. In psychology, differentiation is a person’s ability to become fully autonomous and separate (psychologically, emotionally, spiritually) from their family of origin.

And when it comes to relationships, at the center of every negative and unhealthy relationship dynamic are two people’s lack of differentiation.

Differentiation is an active relational process that allows you to feel yourself as an autonomous separate person. Differentiation means that you understand that your body, perspective, needs, thoughts, feelings, desires are your own; and that you are able to tolerate that your partner is a separate person with different needs and perspectives.

There is a polarity that exists in every relationship: 

Polarities exist everywhere in life. They are not intended to be antagonistic or conflictual in nature. A polarity is like a see-saw; an ongoing, embodied dance of a relationship between two things. This polarity dance changes moment-to-moment, and day-to-day, depending upon our felt-sense of what we need.

When someone puts too much weight on the attachment side of the see-saw, they may minimize their preferences or hide aspects of themselves in order to find or maintain love. If someone weighs too heavily on the autonomy side of the see-saw, they may avoid connection, fear it, or distance themselves from experiencing togetherness. When someone is poorly differentiated, they find themselves in an either/or dilemma: either be myself, or be close.

Differentiation is the embodied balancing of attachment and autonomy. The more differentiated you become, the more you dance inside the polarity. You are able to be connected to yourself (your needs, thoughts, feelings, values, and experience) and be close to someone while experiencing their difference. Differentiation allows you to be close without being reactive, or as Assael Romanelli Ph.D. says, “Differentiation allows you to be big and together.”

How a lack of differentiation impacts relationships.

As a result of early development, many people did not differentiate from their caregivers, which means they may feel anxiety accepting or tolerating the reality that other people are different. People with low levels of differentiation experience high levels of relational anxiety, dissatisfaction, and interpersonal conflict. They tend to be overwhelmed by emotions and experience relational discomfort. Other characteristics of low differentiated people include fusion, being emotionally cut off, and emotional reactivity.

People with high levels of differentiation are flexible and can maintain their “I-position” in intense interactions and relationships. The “I-position” was conceptualized by American psychiatrist and family systems theorist Murray Bowen and is defined as the ability to take a thoughtful stand, whether or not other people agree, and the ability to set clear, calm, and consistent boundaries. Differentiated people can remain regulated and calm in conflicted relationships, resolve relational problems effectively, and reach negotiations and compromises.

Most intimate relationships fail as a result of low levels of differentiation. Without differentiation, relationships cease to grow because the relationship dynamic becomes static and rigid. Without differentiation, couples become entrenched in a power struggle because they can not tolerate that their partner has different needs, temperament, or views on things.

Bowen’s work in family systems is organized around the variety of dysfunctional and disruptive interpersonal phenomena that is caused by low levels of differentiation. While there are many dynamics that result from low differentiation, here are some common ones that can occur in romantic partnerships:

Learning to differentiate.

So, where do we learn differentiation—or our lack thereof?

In psychology, introjection is an unconscious internalization of the thoughts, behavior, or traits of others. It occurs as a normal part of development, such as a child taking on parental values and attitudes. However, it can also be a defense mechanism, and in many instances, introjection creates unconscious behavior, rigidity, anxiety, fixedness, and suffering.

We introject our level of differentiation from our parents and family of origin. Children usually recreate their parents’ level of differentiation or lower, since that is what they are shown. However, due to life circumstances, therapy, or being with a partner with a higher level of differentiation, children can evolve past their family of origin.

To increase your level of differentiation, you must begin to commit yourself to show up very differently in conflict with your partner. You must cultivate a tremendous amount of mindfulness and self-awareness. You must commit yourself to learn to regulate your nervous system, and speak calmly and directly when stating needs and boundaries. Finally, and equally important, you must commit to increasing your acceptance of your partner as separate person and to develop an authentic curiosity about their needs, boundaries, and experience.

If you struggle with differentiation, working with a relational therapist can help you with all of the above. They can also help you to gain awareness about low-differentiated dynamics that may be currently playing out in your relationships, and they can help you to strengthen your “I-position,” so that you have greater capacity to state your needs, boundaries, and values.

Importantly, even though differentiation is so key to healthier relationships, the path of differentiation is a path that you walk alone. That’s the entire point of differentiation. Differentiation is you becoming fully autonomous. In a sense, you become your own family, which often involves a messy intrapsychic surgery of snipping all the threads of unhealthy attachment patterns and strategies that you needed to survive as a child.

Differentiation requires focused work, ongoing awareness, commitment to the process, and often therapy. However, if you commit to this process for yourself, you will be able to remain autonomous while maintaining intimacy.