It turns out it isn't the fear of the other person that keeps most people in bad relationships, it's a person's own fear of being alone.

According to a study published in The Journal of Personality and Social Psychology, it is that fear that keeps people in bad relationships or to settle for less in romantic relationships.

"Those with stronger fears about being single are willing to settle for less in their relationships. Sometimes they stay in relationships they aren't happy in, and sometimes they want to date people who aren't very good for them," said lead author Stephanie Spielmann, a postdoctoral researcher for the University of Toronto's Department of Psychology. "Now we understand that people's anxieties about being single seem to play a key role in these types of unhealthy relationship behaviours."

"In our results we see men and women having similar concerns about being single, which lead to similar coping behaviours, contradicting the idea that only women struggle with a fear of being single," added co-author, Professor Geoff MacDonald of the University of Toronto's Department of Psychology. "Loneliness is a painful experience for both men and women, so it's not surprising that the fear of being single seems not to discriminate on the basis of gender."

As part of the study, they explored how people thought about being single and then developed a scale based on the fear of being single.

The study then showed that "fear of being single predicts settling for less in ongoing relationships, as evidenced by greater dependence in unsatisfying relationships." It also found that "fear of being single consistently predicted romantic interest in less responsive and less attractive dating targets."

The one thing fear did not affect was the idea of wanting a partner who would be a good parent, where people maintained consistently higher standards for parenting."