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When we think about the kind of person we’d like to date, we often list the qualities we most desire in a partner—our deal-makers. But we also have our deal-breakers—qualities that would disqualify someone as a dating prospect, regardless of how many other wonderful traits they have. There has been a great deal of research on deal-makers, but until recently, not much on deal-breakers. In a series of studies, Peter Jonason and colleagues investigated the most common relationship deal-breakers and how they affect dating choices.1

What are the most common deal-breakers for men and women?

In the first study, the researchers just wanted to get a general sense of what traits people were likely to see as deal-breakers. They surveyed 92 college students who were asked to list their personal deal breakers for long- and short-term relationships. Most of the students didn’t name that many—an average of just under five deal-breakers for long-term relationships, and three for short-term relationships.

That first study generated a list of 49 possible deal-breakers. In a second study, a separate sample of 295 students rated the extent to which they felt that each of those 49 traits was a deal-breaker for them. In general, women were more likely than men to identify these traits as deal-breakers. The table below shows the most common ones. They tended to focus primarily on health (STDs, bad smells); dating behaviors (dating multiple partners, already in a relationship); and negative traits (untrustworthy, abusive, uncaring).

Source: Adapted from Jonason et al. (2015), Table 1

Of course, small samples of college students don’t represent most singles. So in a third study, the researchers surveyed a nationally representative sample of 2,744 single American adults. These participants were given a list of 17 traits and were asked to check off the ones they felt were deal-breakers (as many as they wanted). The table below shows the percentage of participants who chose each of the 17 traits, broken down by . Participants chose an average of six deal-breakers, with women choosing slightly more than men.

Source: Adapted from Jonason et al. (2015), Table 2

How do deal-breakers affect our dating choices?

The researchers also wanted to understand how these deal-breakers affect our dating decisions. So they conducted three other experimental studies, varying the deal-breaking information that participants received about potential mates.

In one experiment, 132 adults evaluated profiles of four potential mates who were attractive and successful. They were asked to rate how likely they would be to consider a purely sexual relationship; a short-term relationship; a committed long-term relationship; or a with each of these four people. After the participants made their ratings, they learned that each of the potential mates possessed a specific potential deal-breaker—an unhealthy lifestyle, undesirable personality traits, interest only in a casual sexual relationship when you’re interested in a serious relationship, or vice-versa. Participants then re-evaluated their interest after learning about the deal-breakers.

The results showed that non-dating-related deal-breakers—unhealthy lifestyle, undesirable personality traits—made people less inclined to have any type of relationship with the person, including friendship. The deal-breakers that involved discrepancies between their own and the potential mate's dating intentions, however, only negatively impacted romantic interest. And while one might have expected men to be more willing than women to date someone interested in casual when they wanted something more, the researchers did not observe this.

Men were generally more willing than women to engage in both short- and long-term relationships with each of the potential mates. Finally, women had a more negative reaction than men to learning that a person had negative personality traits.

In their last two experiments, the researchers examined the relative effect of deal-breakers and deal-makers. The question: Are deal-breakers more important than deal-makers in determining romantic interest?

In one study, 193 adults were asked to imagine they had just met someone new, and to rate how learning new pieces of information about that person would affect their likelihood of accepting or rejecting the individual as a short- or long-term relationship partner. Five pieces of information were potential deal-breakers—poor hygiene; short-tempered; has an STD; promiscuous; and drinks excessively—and five were deal-makers—physically attractive; kind; good ; good ; intelligent.

The results showed that the deal breakers had a bigger effect than deal-makers on participants’ interest in a potential mate. However, this wasn’t true for everyone: Those who saw themselves as undesirable short-term mates rated deal makers as more important than deal breakers when considering the person as a short-term mate.

In a final experiment, the researchers varied the relative number of deal-breakers and deal-makers that participants learned about a potential mate (deal-maker:deal-breaker ratios of 0:5, 1:5, 2:4, 3:3, 4:2, 5:1, or 5:0). They then asked 271 adults to consider a situation in which their potential partner had x Deal-makers and y Deal-Breakers. They were asked to rate how likely they would be to consider that person as a friend; a short-term partner; or a long-term partner. Like the previous study, this experiment also found that deal-breakers had a bigger effect on relationship intentions than did deal-makers; this tendency was greater for women than for men.

The researchers interpreted their findings as being consistent with evolutionary theory which posits that women are more discriminating in their choices than men. This was supported by women’s slightly greater tendency to deem various traits deal-breakers and their tendency to be especially affected by the presence of deal-breakers in a potential mate. However, statistically, these gender differences were significant, but fairly small, suggesting that men and women don’t differ very much in terms of their deal-breakers or how important they are in their dating decisions.

This research also shows that when it comes to evaluating potential mates, we don't "accentuate the positive," as the old song goes, but rather, we put more weight on important negative traits.

The big unanswered question in this research is how this operates in people’s actual mate choices. What we say we want in a mate doesn’t always line up with what we really choose. Research on speed-dating has shown little correspondence between the traits people claim they are looking for in a mate and the traits possessed by the people who interest them at an actual speed-dating event.2 In addition, research has shown that people are often willing to agree to a date with a flawed suitor if they believe that person is real, rather than hypothetical.3

Would these deal-breakers really break the deal in a real-life dating context, or are we more willing to compromise than we admit?

Read more articles by Gwendolyn Seidman, Ph.D. on Close Encounters.