Women are programmed to have affairs as a way of testing for better partners, according to research.
Humans, and women in particular, have evolved to pursue affairs in case they decide to leave their partners.
This “mate switching hypothesis” suggests that humans have developed instincts to constantly test their own relationships and check for better long-term options.
This applies particularly to childless women whose choice of partner can have a huge impact on their subsequent ability to raise children, the researchers found.
The US study goes against the widespread assumption that humans are meant to be monogamous and that break-ups are signs of failure.