Practise including the other person in your self-concept

Close relationships develop when you genuinely incorporate the other’s perspectives and resources into how you think — not just spend time with them.

Why it works

Aron’s model holds that closeness is operationally defined as the degree to which a person incorporates the other into their self-concept — borrows their perspectives, skills, and identity. This is not metaphor: research using reaction-time paradigms shows people are slower to distinguish self from close-other attributes the closer the relationship. Practices that deliberately invoke the other’s perspective strengthen this inclusion and deepen the experience of closeness.

How to do it

1. When facing a decision, deliberately invoke the perspective of a close person: "How would [name] see this situation?"
2. Describe a close person’s strengths or capabilities as though they were resources you have access to.
3. In conversation, look explicitly for what the other person knows or does well that you do not — and ask about it.

Evidence

Research using the Inclusion of Other in the Self (IOS) scale found it to be a reliable predictor of relationship closeness, and experimental work found that people’s self-description processing is slower on attributes shared with close others, consistent with the self-incorporation mechanism. (observational)

The self-incorporation mechanism is measured through reaction-time and self-report proxies; whether deliberate IOS-raising practices produce closeness has less direct study than the correlation evidence.

Sources

• Aron, Aron & Smollan (1992), "Inclusion of Other in the Self Scale and the structure of interpersonal closeness", Journal of Personality and Social Psychology

Common mistake

Assuming shared time automatically produces self-expansion — time together without genuine curiosity about the other’s distinct perspective does not produce the inclusion-in-self mechanism.