TORONTO -- Does body language define attraction between people? Or is eye contact a signal of a true connection?

Researchers in the Netherlands who set out to answer these questions found that synchronized heart rate is a more reliable sign of a true connection than eye contact or body language.

To arrive at the findings recently published on online journal bioRxiv, Mariska Kret and her team from Leiden University set up a dating lab at three separate events in the Netherlands: a music festival, a science and arts festival, and a science film festival.

They had a total of 140 heterosexual participants, between the ages of 18 and 37, who sat in pairs across from each other with a visual barrier blocking their view. They were allowed to see each other for three seconds, then had to rate their partner on an attraction scale of zero to nine.

The pair could then look at each other for two minutes and spend another two minutes talking to each other.

During the interactions, researchers used eye-tracking glasses to see how long the participants looked at each other and to track their expressions. The couples also wore sensors that measured their heart rates and the conductivity of their skin.

Kret’s team found that looking at each other, smiling, laughing or gesturing with hands did not predict attraction. Instead, couples who were more attracted to each other had synchronized sweating levels and heart rates.

The results offered a glimpse of how women and men interact differently with each other.

The study found that women are more expressive, smiling and nodding more at their male counterpart. Men, on the other hand, were more likely to stare at their partner’s head and eyes. Women in the study were more likely to look around than the men.

In the end, a total of 58 out of 140 people were interested in dating their partner – 53 per cent of men in the study wanted another date with their partner compared to the 34 per cent of women.