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Why Breaking Up Can Be So Hard to Do

Examining progression bias in relationships.

Key points

  • We have a natural tendency, the progression bias, to keep moving forward with a relationship and ignore warning signs of trouble.
  • This progression bias is driven by evolutionary, cognitive, emotional, and social forces.
  • Even when we do have doubts about moving on with a relationship, our social networks will encourage us to push forward anyway.
Dejan Dundjerski/Shutterstock
Source: Dejan Dundjerski/Shutterstock

After the party for her twentieth wedding anniversary, Angie sits at her dresser, wondering how she had got to this point in her life. Steve was hardly the kind of man she had imagined marrying, not at all her type.

She never understood why she even dated him in the first place. Sure, they had fun together, but she saw the red flags early on, even though she chose to ignore them. There was no one else on the horizon at that point, and her friends all told her what a catch he was.

She kept on dating him, and before she knew it, they were living together, and then they got married. How many times had she thought about leaving him in the last 20 years? And yet, she never did.

Why Do We Stay When We Want to Leave?

We’d like to think of the Western courtship ritual of dating and cohabiting as a test for whether a couple is compatible for marriage. But in a recent article published in the journal Personality and Social Psychology Review, Canadian psychologists Samantha Joel and Geoff MacDonald argue that most people simply move through the various stages of relationship building without any serious consideration of whether their partner is right for them in the long run. They refer to this tendency to keep moving forward in a relationship as progression bias.

Joel and MacDonald point out that people can easily describe what their ideal partner would be like. But in reality, people are willing to date a wide range of potential partners that don’t even come close to meeting their ideal. Instead, once they start dating someone, they revise their ideal to approach the qualities of their new partner. Furthermore, they tend to look past their partner’s flaws, viewing them in a far more positive light than an objective observer would.

As the relationship advances, couples invest more and more into it, making it costly to leave. Even couples in friends-with-benefits arrangements often end up in a long-term committed relationship as they share more and more of their life together. This is because intimate sex partners quickly develop an attachment to each other.

The authors also note that couples rarely give much deliberative thought to their decision to move in together. Instead, as the relationship develops, they spend more time at each other’s place, until it simply makes sense to share one space instead. Although people think of cohabitation as a kind of trial marriage, it can be very difficult to leave after moving in together. Instead, most couples get married after an appropriate amount of time has passed, often under social pressure from friends and family. “So, when are you two going to tie the knot?”

People in committed relationships often prefer to stay in a less than ideal situation even when attractive alternatives are available. Likewise, many find it difficult to leave abusive relationships. Even when couples do break up, the chances of them getting back together again are fairly high.

Why Does Progression Bias Occur?

Why do people show a progression bias in relationships? Joel and MacDonald offer evolutionary, cognitive, emotional, and social explanations.

At the evolutionary level, it makes sense that those who enter into a committed intimate relationship are more likely to have offspring, and thus pass on their genes, than those who don’t. If you hold out until you find someone who meets your ideal, you may never mate at all.

At the cognitive level, people can get quickly overwhelmed when they have to decide among many choices. The typical young adult encounters dozens of potential mates each day. In the face of an overwhelming number of options, people make “good enough” choices instead, whether buying a new smartphone or searching for a mate.

This cognitive explanation dovetails with the evolutionary one. Our hunter-gatherer ancestors lived in small groups. Choices were few, so expectations would have been low, and settling for good enough would have been the norm.

At the emotional level, many people experience a fear of missing out on a romantic opportunity. Thus, they would rather risk rejection when approaching a potential partner rather than miss an opportunity for romance, even if it leads to a relationship that’s less than ideal.

Once a couple starts dating, they go through the processes of infatuation and attachment. People quickly fall in love with partners they just started dating, and this infatuation helps drive the relationship to higher and higher levels of commitment. Even after infatuation fades, attachment keeps the couple bound together.

Within months, people develop an attachment to their new partner, such that they feel reassured in their presence and anxious or restless in their absence. Long after the infatuation has faded, feelings of attachment continue to bind a couple together, making it difficult to break up the relationship, even when the situation is far from ideal.

At a social level, there are many advantages to being coupled and many disadvantages to being single. Friends and family will keep asking when you’re going to find someone nice and settle down. Likewise, many social events are set up for couples, and attending without a partner can be awkward. Furthermore, married couples enjoy all sorts of financial benefits, such as lower taxes, that singles do not.

Is Progression Bias Avoidable?

Dating may seem like a process for trying out various potential partners to find the best fit for marriage. However, Joel and MacDonald argue, careful observation shows that this is not the case for most people.

Rather, we show a progression bias in relationship formation. Once we find a partner who responds to our advances, we move through the stages of dating, sexual intimacy, cohabitation, and marriage as if on a conveyor belt. Although we’re supposed to be on the lookout for signs of trouble, we disregard those red flags even when they clearly tell us it’s going to be a rocky road ahead.

In the end, it’s in our nature to progress forward in relationships, and even if we try to resist, our genes and our social networks push us onward anyway.

Facebook image: Dejan Dundjerski/Shutterstock


Joel, S. & MacDonald, G. (2021). We’re not that choosy: Emerging evidence of a progression bias in romantic relationships. Personality and Social Psychology Review. Advance online publication. DOI: 10.1177/10888683211025860

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