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7 Ways Your Relationship Can Change Who You Are

For better, or in some cases, for worse.

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We’ve all got that friend who never paid attention to football, starts to date a new guy, and suddenly never misses a game. Or what about that former smoke-break buddy who finally quit, but says it has nothing to do with his new non-smoking girlfriend? Are these mere coincidences, or is something else at work?

Sure, relationships are dynamic, changing over time and with new situations. But are people in relationships dynamic as well? In other words: Has your relationship changed you?

Research suggests that people are very much affected by those around them, and not just behaviorally. A growing body of scientific evidence suggests that people’s self-concepts actually change when they’re a relationship. To evaluate your own self-change, and to understand others’, here’s what you need to know:

  1. Falling in love facilitates self-change. The experience of falling in love is exhilarating, perhaps because it promotes a startling degree of self-change (Aron, Paris, & Aron, 1995). You go from you to a new you, one whose self-concept has integrated aspects of your partner. Your partner's achievements or sorrows are experienced as somewhat your own, and your preferences grow to embrace his or hers.
  2. Some people are more prone to self-change than others. We’re all affected by the people we love, but some of us more so. Evidence suggests that individuals who are high on attachment anxiety (i.e., they fear abandonment and may question their own self-worth) tend to have highly malleable self-concepts in relationships (Slotter & Gardener, 2012).
  3. Healthy relationships involve self-expansion. If you’ve ever thought that being with someone makes you a better person, you’re tapped into the idea of self-expansion, which refers to positive self-growth (Aron, Aron, Tudor, & Nelson, 1991); who you are today is a richer person with more positive aspects than before you met your "better half."
  4. Unhealthy relationships might make you a worse person. Self-growth doesn’t always mean gains in positive traits or behaviors (Mattingly, Lewandowski, & McIntyre, 2014). Sometimes self-growth can pull you towards unhealthy habits or behaviors, or make you more anxious, whiny, crude, or hurtful. The potential negative changes from relationships reveal the importance of your partner choice. In entering a relationship, you risk becoming someone you might not wish to be.
  5. Healthy relationships can lessen bad habits. Besides self-concept growth, the self can experience pruning, or the lessening of unfavorable qualities (Mattingly et al., 2014). Maybe you were once a loud talker, a nail biter, or a heavy drinker, and being with your partner has changed those annoying or unhealthy habits. Such relationship-based pruning is considered a way of improving the self.
  6. Relationships can lead to self-constriction. As much as a new love can pare bad habits, it might cut away some good qualities, too. New research suggests that sometimes being in a romantic partnership means losing favorable aspects of the self (Mattingly et al., 2014). People might become less trusting or less friendly; their overall self-concept may lose positive qualities as they become closely tied to their romantic partner.
  7. Break-ups require massive self-change. It hurts, but it's true: A loss of love can mean a loss of self. Many people experience serious self-confusion (“I don’t know who I am anymore”) as their self-concept shrinks post-breakup (Lewandowski, Aron, Bassis, & Kunak, 2006). When adjusting to a breakup, people face the hard work of disentangling the parts of their self-concept they wish to keep from those that were tied to their former partner and are charged with the task of rebuilding a new sense of self.

It’s clear that our self-concepts aren’t as stable as we might think and that our significant others have a great deal of power in shaping our future selves. We are profoundly affected by those we love, responding (unconsciously) to their influence and becoming different people over time. All of this echoes the importance of choosing a partner carefully, one who has traits and characteristics that you aspire toward so that you might change in a favorable direction.

Keep in mind that as much as you're under the influence of your partner, your partner is under your influence as well. So use your power wisely, and choose a partner who already is what you need and are looking for, so that you can devote your energy to enjoying your time together, rather than trying to change that person into someone else.


Aron, A., Aron, E. N., Tudor, M., & Nelson, G. (1991). Close relationships as including other in the self. Journal of Personality and Social Psychology, 60, 241–253.

Aron, A., Paris, M., & Aron, E. N. (1995). Falling in love: Prospective studies of self-concept change. Journal of Personality and Social Psychology, 69, 1102-1112.

Lewandowski, G. W., Aron, A., Bassis, S., & Kunak, J. (2006). Losing a self‐expanding relationship: Implications for the self‐concept. Personal Relationships, 13, 317-331.

Mattingly, B. A., Lewandowski, G. W., & McIntyre, K. P. (2014). “You make me a better/worse person”: A two‐dimensional model of relationship self‐change. Personal Relationships, 21, 176-190.

Slotter, E. B., & Gardner, W. L. (2012). How needing you changes me: The influence of attachment anxiety on self-concept malleability in romantic relationships. Self and Identity, 11, 386-408.