A new study has shown that sweaty palms, along with your heartbeat, could be your most attractive feature.
Researchers conducted a dating experiment in the Netherlands. They recruited heterosexual participants to participate in real-life blind dates. Participants would meet their potential partner in a "dating cabin" while wearing sensors that measure the physiological dynamics of the couple.
These sensors were equipped with eye-tracking glasses and embedded cameras that recorded how each person laughed, smiled, and acted with their partner.
Each participant wore sensors to monitor heart rate and skin conductance (aka electrodermal activation) to measure how skin perspiration changed in response to psychological or physiological stimulation.
The researchers looked for signs of physiological synchroy, which is the secret choreography of non-verbal cues between people that emerge when they connect or share experiences.
"We believe that if there is a feeling of attraction, then there must be physical manifestations of interpersonal attraction in real life," researchers led by Eliska Prochazkova, psychologist at Leiden University, write in their paper.
The team believed that these manifestations could manifest in a variety of overtly synchronous behaviors. Attracted participants might mimic or reciprocate their partners' physical expressions such as smiles and laughter, eye gazing, eye gazing, nodding, or other gestures.
It didn't work out that way.
Prochazkova says that none of these signals could predict the degree to which someone is attracted to another. This is determined by invisible signals like heart rate and skin conductance.
Each blind date saw the participants sit on opposite sides of a table. A barrier was placed between them for a few seconds to allow them to see each other before closing again. Participants were then asked to rate their attraction towards the other participant.
The barrier was opened once again and participants were able to speak freely for a few minutes, followed by another discrete attraction rating, then they were instructed to gaze at each other for 2 minutes, before rating them again.
During this sequence of interactions, the eye tracking glasses recorded their exchanges while the electrodermal and electrocardiographic sensors monitored their heart rate, and skin conductance.
Researchers say that these are the best measures to get the job done.
Prochazkova explains, "We discovered that if the partners were attracted to each other, their heart beats synchronized with their partner's," Prochazkova said.
"If one person's heart beat increases, the other's will follow suit." If their heart rates decreased, so did the other's.
Researchers found that perspiration changes in skin followed the same pattern of syncing, even though explicit gestures like smiling or laughing did not. This may indicate the importance subconscious physiological coupling for the development of romantic attraction.
The team believes that it is possible for more subtle forms of physical mimicry to one another's behavior and gestures - such as laughing at the same joke - to only be superficial levels of synchrony.
However, microexpressions that are far more subtle could communicate and reflect a deeper emotional connection between people. Researchers acknowledge that there is much to be learned about this psychological phenomenon, including whether synchrony can cause attraction or vice versa.
It is important to remember that this blind date in a controlled cabin was an artificial setting, but for studies such as these, that is exactly what matters. The team suggests that future studies might be even more strict.
They write that this study is the first to attempt to detect attraction using physiological and eye-tracking measures. Researchers are advised to replicate their findings in a controlled laboratory setting with larger samples before trying to use them in the field.
We know for now that two people can communicate a lot when they are together. Sometimes, however, we connect with someone special on a mysterious wavelength.
The researchers conclude that the findings suggest that physiological states of the interacting partners synchronize to mutual alignment at the moment-by-moment level.
"During these moments, a combined mental state can potentially facilitate the feeling of a click and attraction."
These findings were published in Nature Human Behaviour.
