Why Breakups Feel Like Identity Collapse

The science of how relationships reshape our sense of self and finding yourself again after a breakup

Why does heartbreak still feel so intense, even months after the relationship is over? Why does it leave you feeling like the ground has shifted beneath you?

A lot of people find themselves wondering, “It’s not like someone died, so why does it hurt this much?” And while a breakup isn’t the same as a death, research shows that the emotional and psychological effects often overlap. In her paper Romantic Breakups, Heartbreak and Bereavement, researcher Tiffany Field points out that heartbreak can bring on trouble sleeping, difficulty concentrating, intrusive thoughts, numbness, low mood, and anger—many of the same experiences people go through during grief.

Part of what makes breakups so disorienting is that it’s more than losing the person. You also lose the version of yourself that existed in that relationship. We grow and evolve through the people we’re close to. Romantic partners, in particular, often shape how we see ourselves and how we move through the world.

So when a relationship ends, it’s no surprise that many people say they feel lost. Some mention they don’t even recognise themselves anymore, or that they feel incomplete. And it’s not just in their head. In fact, researchers actively study how much of the self is lost after a breakup, how it's regained, and how this process relates to our overall wellbeing.

In Livewired, neuroscientist David Eagleman compares heartbreak to drug withdrawal. He writes:

People you love become part of you—not just metaphorically, but physically. You absorb people into your internal model of the world. Your brain refashions itself around the expectation of their presence. After the breakup with a lover, the death of a friend, or the loss of a parent, the sudden absence represents a major departure from homeostasis. (…) Just like feeling the waves after you’ve departed the boat, or craving the drug when it’s absent, so your brain calls for the people in your life to be there.

Relationships change our self-concept, and when they end, it can feel like losing our footing. Recognising that matters. Because when we start to understand how a relationship shaped us, and what it meant, it gets easier to actively rebuild a sense of self that carries those good parts forward, even as we let go of what’s no longer there.

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Over a century ago, in his seminal Principles of Psychology, William James observed that the people around us reflect back different aspects of who we are, writing that “a man has as many social selves as there are individuals who recognize him.” And modern psychology has expanded on this, offering frameworks that explain not just how relationships shape us, but why breakups leave us feeling so disoriented, and why it takes time to find our way again.

One example is the Michelangelo Phenomenon, which describes how close partners can help shape each other toward their ideal selves through their perceptions, encouragement, and everyday interactions. Like Michelangelo carving away stone to reveal the figure within, a good relationship often brings out our best qualities and helps us feel like we’ve changed for the better.

Closely related is the Self-expansion Model, which suggests that relationships literally expand our sense of sense. Through a meaningful relationship, we might pick up new habits, hobbies, perspectives, ways of thinking, or social circles. Over time, those things become parts of our identity. We start seeing ourselves differently, taking on new roles, trying new things, and relating to the world in new ways. We might become braver, more playful, more open, or more honest. Perhaps our partner brought out a side of us that felt more alive. Maybe they helped us feel safe enough to express parts of ourselves we had kept hidden. Their presence might have made us feel more confident or spontaneous in ways that surprised us. Or maybe being accepted by them made it easier to accept parts of ourselves we’d previously rejected.

There’s an interesting study from the early 1990s that illustrates just how dramatically our sense of self can shift in close relationships. Researchers asked participants to distinguish between themselves and their spouses. Married individuals actually took longer to answer me or not me decisions about traits they didn’t share with their partners, compared to traits they did share. It turns out, when two people’s lives intertwine, those boundaries get blurry.

So, when a relationship ends, it makes sense that our sense of self can suddenly feel less clear, less anchored. The parts of our identity tied to that relationship fall away, and that can affect our wellbeing in ways we might not expect. Research backs this up. In a series of studies, psychologists explored what happens to our sense of self after a breakup, particularly when that relationship had contributed to our personal growth. They found that the more people felt their relationship helped them expand and grow, the harder it was to maintain a clear, steady sense of self once it ended. Even after controlling for emotional closeness, it was this personal growth element that stood out as one of the strongest predictors of post-breakup identity struggles.

And this might help explain why heartbreak isn’t just about missing someone’s presence. It’s about losing the version of ourselves we were with them—and having to figure out what parts of that person we want to keep, what we need to rebuild, and how to carry those parts forward on our own.

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The missing piece in most breakup advice

One reason the usual breakup advice—cut contact, stay busy, move on—tends to fall flat is that it overlooks the full scope of what’s actually been lost. It treats heartbreak like it’s only about missing the person, without acknowledging how our identity and sense of self can be affected, too.

And this is where frameworks like self-concept change in relationships can be so helpful. Because when a relationship reshapes how we see ourselves and how we move through the world, its ending isn’t just about grief. It also creates a kind of identity rupture. Recovery, then, requires more than just letting go of the other person.

First, these models highlight the importance of getting clear on how the relationship changed us: what parts of ourselves felt good or came alive in that connection, what feels missing now, what’s harder to access, and what leaves us feeling a little less whole without that bond.

Second, once we can get clear on those shifts, it becomes easier to make choices about who we want to be now: how we want to live, connect, and keep growing.

And third, these ideas invite us to find new ways to access those meaningful parts of ourselves—whether through other people, fresh experiences, new habits, or reconnecting with those aspects internally.

Maybe before the relationship, we struggled to accept affection or didn’t even know what real support even looked like. Slowly, we let ourselves be cared for. We became more open, more generous, more expressive. And now, with that relationship gone, it can feel like those parts of us disappeared too. We might find ourselves wondering whether we’ll ever know how to be that person again, or whether anyone else will bring those parts out in us. It can feel like they took something with them when they left, and now those parts are locked away, just out of reach.

That’s a common scenario. And it shows how our sense of self changes within a relationship and how it can feel disrupted after it ends. Moving forward gets easier when we recognise how the relationship shaped us, why those changes mattered, and how we might carry those qualities into other parts of our life. For example, it could involve actively practicing the qualities the relationship helped bring out in us, whether that’s being more affectionate, open, curious, or kind, without depending on someone else to unlock those parts again. It means intentionally bringing those aspects back into everyday life.

This also offers a new way of thinking about heartbreak. Not just as something to “get over,” but as something that reveals what we care about in ourselves, how we’ve related to others, and how we want to move through life moving forward. One of the most meaningful ideas from the self-expansion model is the reminder that growth isn’t tied to one person or relationship. It’s about recognising the parts of ourselves that emerged in that connection and finding ways to keep them present.

Which leaves us with a powerful question to carry forward:
How do I move through the world in a way I only allowed myself to explore because someone else was there?

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