Self-expansion is the idea that people have a basic drive to grow, by learning new things, gaining new perspectives, and building new skills, and that close relationships are one of the main ways they do it. Early in a relationship, getting to know someone new is itself expanding. Later, couples can recreate that feeling by trying new and mildly challenging things together, which research links to feeling better about the relationship.

Where the idea comes from

Self-expansion theory comes from psychologists Arthur Aron and Elaine Aron. A 2022 review by their team describes two core ideas. First, people have a basic desire to expand the self by growing their abilities, perspectives, and resources. Second, close relationships are a major way this happens, because a partner's skills, views, and identities become partly "included in the self" [1]. The review also notes that most studies have not tested how universal the model is across cultures.

To test one practical prediction, Aron and colleagues ran a newspaper survey, a door-to-door survey, and three lab experiments. In the surveys, couples who reported more shared "exciting" activities also reported higher satisfaction, and lower relationship boredom helped explain the link. In the experiments, couples who spent about seven minutes on a novel, physically challenging task together reported bigger increases in relationship quality than couples who did a more mundane task [2]. The researchers suggest this may help explain why relationship quality often drops after the honeymoon period: novelty fades and boredom sets in.

A related line of research from Aron's group showed that structured, gradually deeper self-disclosure created more closeness between strangers than small talk [3]. That study is the source of the famous "36 questions," and it measured closeness, not falling in love.

What it looks like in real life

Self-expansion doesn't require skydiving. Everyday examples include:

  • Taking a beginner class together, such as dance, pottery, or a language.
  • Cooking a cuisine neither of you has tried.
  • Hiking a new trail or exploring a part of town you've never visited.
  • Learning about your partner's hobby from them, and teaching them yours.
  • Planning a small project together, like a garden or a trip.

The common thread is something new, a little challenging, and shared.

What to do with it

  1. Swap one routine date for something new each month. Our date night generator can help you brainstorm.
  2. Keep it low-pressure. Being bad at something together is part of the fun.
  3. Debrief afterward. "What surprised you?" turns an activity into a conversation.
  4. Pair novelty with talk. Playful questions from our fun and playful prompts work well on the drive home.
  5. Don't use novelty to dodge real issues. If something painful needs attention, new activities help most alongside honest conversation.

When to get professional help

If you've tried new things together and still feel disconnected, or one of you no longer wants to try, deeper issues may be at play. A couples therapist can help; see our guide to getting help. If you feel unsafe with your partner, visit Help Now.