Erik Erikson was a 20th century psychologist. He analyzed and divided the human experience into eight stages of development. Each stage has a unique conflict and a unique result.

One such stage — intimacy versus isolation — points out the struggle young adults have as they try to develop intimate, loving relationships. This is the sixth stage of development, according to Erikson.

As people pass through these stages, Erikson believed they gained skills that would help them succeed in future stages. However, if they had trouble attaining these skills, they might struggle.

In the intimacy versus isolation stage, according to Erikson, success means to have healthy, fulfilling relationships. Failure means experiencing loneliness or isolation.

While the word intimacy might evoke thoughts of a sexual relationship, that’s not how Erikson described it.

According to him, intimacy is a loving relationship of any sort. It requires sharing yourself with others. It can help you develop deeply personal connections.

Yes, in some cases, this may be a romantic relationship. Erickson believed this stage of development happens between ages 19 and 40 — which is precisely when most individuals might be looking for a lifelong romantic partner.

However, he didn’t think romance was the sole endeavor of building intimacy. Instead, it’s a time when people can develop sustaining, fulfilling relationships with people who aren’t family.

Those who were your “best friends” in high school may become cherished elements of your intimate circle. They might also fall out and become acquaintances. This is a time during which those distinctions are often made.

Isolation, on the other hand, is a person’s attempt to avoid intimacy. This may be because you fear commitment or are hesitant to open yourself up in an intimate way to anyone.

Isolation may prevent you from developing healthy relationships. It may also be the result of relationships that fell apart, and can be a self-destructive cycle.

If you were harmed in an intimate relationship, you may fear intimacy in the future. That can lead you to avoid opening yourself up to others. In turn, that may cause loneliness — even eventual social isolation and depression.

Intimacy is a choice to open yourself up to others and share who you are and your experiences so that you can create lasting, strong connections. When you put yourself out there and have that trust returned, you develop intimacy.

If those efforts are rebuked, or you’re rejected in some way, you may withdraw. Fears of being dismissed, spurned, or hurt may lead you to separate yourself from others.

Ultimately, this can lead to low self-esteem, which may make you even less likely to venture out to develop relationships or new friendships.

Erikson believed that in order to continue developing as a healthy individual, people need to successfully complete each stage of development. Otherwise, they’ll be stuck and may be unable to complete future stages.

For this phase of development, that means you need to learn how to develop and maintain healthy relationships. Otherwise, the remaining two phases of development may be in jeopardy.

Isolation is often the result of a fear of rejection or dismissal. If you’re afraid that you’ll be turned down or pushed away from a friend or potential romantic partner, you may avoid interactions entirely.

This can ultimately lead you to avoid all future attempts at forming relationships.

Moving from isolation to intimacy requires you to resist the tendency to avoid others and skirt difficult relationship questions. It calls on you to be open and honest with yourself and others. That is often difficult for people who are prone to isolating themselves.

A therapist may be helpful at this point. They can help you understand behaviors that might be preventing intimacy, and help you develop strategies to move from isolation to intimate, fulfilling relationships.

Erikson believed that not fulfilling any stage of development would present problems in the future. If you weren’t able to develop a strong sense of self-identity (stage five), you might have a hard time developing healthy relationships.

Trouble at this stage of development might prevent you from nurturing individuals or projects that will “leave your mark” on future generations.

What’s more, long-term isolation can be detrimental to more than your mental health. Research shows that loneliness and social isolation can cause cardiovascular disease.

Some people may be able to have a relationship, despite not building strong, intimate bonds. But that might not be successful in the long run.

One study found that women who were unable to develop strong intimacy skills were more likely to be divorced by midlife.

Healthy, successful relationships are the result of many elements of development — including having a sense of identity.

Building those relationships also depends on knowing how to communicate openly and honestly. Whether you ascribe your development to Erikson’s philosophy or not, healthy relationships are beneficial for many reasons.

If you struggle to form or maintain relationships, a therapist may be able to help you.

A trained mental health expert can help you work through a tendency to isolate yourself. They can also help prepare you with the proper tools to form good, long-lasting relationships.