A person’s relationship history may offer clues about how they treat others. But experts warn that a string of failed relationships alone is not enough to diagnose narcissism. When trying to understand whether someone displays narcissistic traits, one of the most revealing clues may not be what they say about themselves, but what they say about the people who came before them.

 Their past relationships with partners, friends, family members and colleagues may reveal patterns that are difficult to notice during a first encounter. Dr Olivia Remes, a psychologist at the University of Cambridge, says people with strong narcissistic traits may struggle to maintain healthy relationships over time.

 “Their relationships can be troubled, and narcissists try to take advantage of others for their own gain,” she says. A constant need for attention and admiration, difficulty accepting criticism and a tendency to shift blame can gradually undermine relationships. At first, however, the person may appear charming, confident and highly sociable.