People are hardwired to fall out of love and move onto new romantic relationships, shows research from Saint Louis University.
"We have a mechanism in our brains designed by natural selection to pull us through a very tumultuous time in our lives," said Brian Boutwell, associate professor at Saint Louis University.
"It suggests people will recover; the pain will go away with time. There will be a light at the end of the tunnel," he added.
Boutwell and his colleagues examined the process of falling out of love and breaking up and moving on to develop a new romantic relationship.
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 are not genetically their own," the authors wrote.
"Men are particularly sensitive to sexual infidelity between their partner and someone else," Boutwell said. "That is not to say women do not get jealous. They certainly do but it is especially acute for men regarding sexual infidelity."
On the other hand, a woman may be more likely to break up if her partner has been emotionally unfaithful partly because of evolutionary reasons.
Over the deep time of evolution, natural selection has designed mate ejection in females to avoid the loss of resources, such as help in raising a child and physical protection, that their mates provide.
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," Boutwell noted.
In addition, some people might be more likely than others to fall out of love or have problems moving. The ability to break up and find someone new to love lies along a continuum, influenced by environmental and genetic factors.
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.
Falling out of love, Boutwell contended, might be compared to asking a cocaine addict to break his or her habit.
"Ultimately, trying to move on from a former mate may be similar in some ways to an attempt at breaking a drug habit," the authors noted.
Boutwell urged more research into lost love to better understand the difficulties that can creep into a romantic relationship.
"If we better understand mate ejection, it may offer direct and actionable insight into ways in which couples can save a relationship that might otherwise come to a stultifying and abrupt halt," he concluded.
