We’re often told that it’s important to “know thyself.” Although this advice might sound a bit clichéd, it turns out that knowing who we are makes a difference in our romantic relationships.

This general sense of feeling like “I know who I am” is referred to as self-concept clarity. Past research suggests that people who feel like they have a clearer sense of who they are tend to be more satisfied with their romantic relationships and more committed to their partners. In recent papers published in Personality and Social Psychology Bulletin, my collaborators and I found that there are certain times when having high self-concept clarity is especially important in relationships, and that our relationships can in turn shape our self-concept clarity.

Abundant research suggests that when people change, they feel happier with their relationships when their partners support that change. However, less is known about what predicts whether a partner will be supportive in the first place – are certain types of people especially likely to support a partner’s changes? We hypothesized that people with low self-concept clarity might actually seek to undermine their partner’s changes.

Why might this be? In a previous paper, my collaborators and I found that people with low self-concept clarity resist having experiences that could change their sense of who they are. Our new paper found that people low in self-concept clarity worry that if their partner changes, they will also have to change. Unfortunately, their lack of support for their partner’s change erodes relationship quality. When we followed participants for 9 months, we found that those with low self-concept clarity undermined their partner’s changes over time. (For example, if their partner had decided to pursue art, they were more likely to make negative comments about their partner’s paintings or schedule other activities for the two of them at the same time as their partner’s art class.) This lack of support resulted in their partner feeling less satisfied with the relationship and less committed by the end of the study. And it was not only the partner who was unhappy with the relationship – the person who had undermined the change also felt less satisfied and committed. So, people with low self-concept clarity tended to undermine their partner’s changes because they worried about having to change themselves, but this made both people feel worse about the relationship in the long run.

Knowing oneself is important for relationship dynamics, but do relationship dynamics also influence how well we know ourselves? In a second paper, we examined how the ways people relate to their partners influence their self-concept clarity. Attachment theory suggests that people vary in the ways they think about their relationships. Individuals high on attachment anxiety tend to desire extreme closeness with others but fear rejection, whereas those high on attachment avoidance tend to distrust others and are hesitant to become too close to others. Individuals with low levels of both attachment avoidance and anxiety are said to be securely attached. Although past research has explored how attachment anxiety affects the self, less work has examined whether attachment avoidance might adversely affect people’s sense of who they are.

Attachment avoidance might be critical for self-concept clarity because one of the ways that we understand who we are is through other people knowing us. If avoidant individuals fear intimacy, their partners may not know them well enough to give them self-affirming feedback. Thus, we hypothesized that avoidant individuals might experience lower self-concept clarity, because they are less likely to get the kinds of feedback from their partners that affirms their sense of self. In one study, we brought couples into the lab and directed each partner into a separate room. We then asked each person to list 10 answers to the questions “Who am I?” and “Who is my partner?” (Some common example responses include “funny,” “caring,” and “worrier”). This enabled us to see how well people really know their partners – how many items on Partner A’s list describing themselves showed up on Partner B’s list describing Partner A? We found that the partners of avoidant individuals really did not know them as well as the partners of less avoidant individuals, and this in turn predicted lower self-concept clarity. In a second study, we followed participants longitudinally; those who were more avoidant at the beginning of the study reported later on that their partners did not know them, which in turn predicted lower self-concept clarity.

Taken together, this set of studies suggests that knowing yourself plays an important role in relationships. People who feel like they know who they are tend to be more supportive when their partners are changing; likewise, the types of people who are comfortable with being close to a partner tend to have a clearer sense of who they are. So, perhaps it’s worthwhile after all to really know who we are, both for ourselves and for our closest relationships.

Lydia Emery is a graduate student at Northwestern University. Her research focuses on the intersection between the self-concept and romantic relationships, as well as how socioeconomic status affects people's relationship dynamics.