Psychologist Explains The Science Behind Why We're Drawn To People Already In Relationships

A psychologist has broken down why so many people find themselves drawn to those who are already taken, even when they don’t mean to.

It’s a strange pattern that many recognize — you can go ages without much attention while single, but the moment you get into a relationship, suddenly more people start sliding into your DMs or showing interest.

For some, it’s the opposite. They catch themselves being more attracted to someone as soon as they find out that person already has a partner.

The good news is, this doesn’t mean anything is “wrong” with you, and according to experts, it’s actually grounded in science.

Psychologists call it ‘mate choice copying’, and while it might sound like a bit of a stretch, researchers point out that it’s not just humans who experience it — many animals follow the same behavioral patterns.

Psychologist Eliose Skinner explained to Metro: "Mate choice copying is defined as the probability of choosing a mate being increased by others' choice of that person, in other words, an individual copies another's mate choices."

There's a biological explanation to the odd attraction phenomenon Getty Stock Image

"Basically, if someone fancies that person, you're more likely to fancy them because they appeal to more people than just you. It sounds reductive, but there's biological proof," she added.

This instinct shows up in real-life dating all the time, no matter what modern trends like ‘dry begging’ or ‘hamstering’ suggest about relationships.

"It's been documented in many species, from fish and birds to primates," relationship psychologist Limor Gottlieb told the outlet.

The idea is that if a man is seen as “chosen” by a woman, it signals that he has desirable traits and is worth pursuing.

Experts note that both men and women can experience this, but according to Gottlieb, women are generally more affected by it. She explained: "In our ancestral environment choosing a mate was a high-stakes decision, due to their high maternal investment - they invested more in children from pregnancy to gestation and years of child-rearing,"

"So women looked for hidden qualities and cues like commitment, loyalty, provisioning, and intelligence, that aren't obvious at a glance."

Men, however, are said to rely more heavily on visible signs like health and youth when making their choices. Gottlieb explained this by saying: "That's why female mate choice tends to be more socially influenced, while male mate choice is more visually calibrated."

Skinner also noted that people who lack relationship experience or who tend to look for reassurance from others are often more vulnerable to mate choice copying.

Of course, relying on this instinct can come with drawbacks. As Gottlieb warned: "It helps speed up decision-making but it doesn't guarantee compatibility,"

Someone may appear more desirable than they actually are Getty Stock Image

"Someone may look desirable in public, yet not be a healthy long-term partner in private."

She emphasized that true compatibility in a long-term partnership depends on things like shared values, loyalty, and genuine commitment. She also pointed out: "Not to mention, if someone leaves a partner for you, there's always the risk they'll repeat that behaviour again."

When this instinct goes beyond attraction and becomes action, it crosses into what’s called ‘mate poaching’, which is actively trying to take someone else’s partner.

According to Gottlieb, about one in five relationships actually start this way. She explained: "Those who engage in mate poaching score higher in narcissism, extraversion, unfaithfulness and openness to new experiences," describing it as a type of ‘short-term mating strategy’ rather than a foundation for lasting love.