A new study has suggested that people are hardwired to fall out of love and move onto new romantic relationships.

The study conducted at Saint Louis University Medical Center examined the process of falling out of love and breaking up, which they call primary mate ejection, and moving on to develop a new romantic relationship, which they call secondary mate ejection.

Brian Boutwell, Ph.D., associate professor of criminology and criminal justice and associate professor of epidemiology at Saint Louis University, asserted that their review of the literature suggests that they have a mechanism in their brains designed by natural selection to pull them through a very tumultuous time in their lives and it suggested that people will recover and the pain will go away with time.

Drawing largely upon the field of evolutionary psychology, researchers observed that men and women might break up for different reasons. For instance, a man is more likely to end a relationship because a woman has had a sexual relationship with another man. For evolutionary reasons, men should be wired to try and avoid raising children that aren't genetically their own.

Boutwell said that Helen Fisher's work has revealed that this circuitry in the brain, which is deeply associated with addictive behaviors, also is implicated in the feelings associated with romantic attraction and may help explain the attachment that often follows the initial feelings of physical infatuation with a potential mate.

Sometimes both men and women end a relationship for the same reason. For instance, neither gender tends to tolerate or value cruelty on the part of their partner.

Brain imaging studies of men and women who claimed to be deeply in love also provided important clues about dealing with breakups. Functional MRIs showed an increase in neuronal activity in the parts of the brain - the pleasure areas - that also become active with cocaine use.

In an additional attempt to understand what is going on inside the brain when a relationship ends, Boutwell examined research regarding the impact of a group of antidepressant medications called selective serotonin reuptake inhibitors (SSRIs) on romantic love. The use of SSRIs can potentially lower levels of dopamine, norepinephrine.

The study is published in the issue of the Review of General Psychology.