Love at first sight can be understood as the attraction of a man and a woman to each other as soon as they meet. So, can two people actually have a good feeling “at the same time”? What is the mechanism behind this?
With this question in mind, scientists at the Hebrew University of Israel conducted related research. By looking at indicators of sweating and physical changes in both men and women on a date, they found that, in fact, those who had a crush on each other reached a physiological “synchronization” within two minutes.
That is, people who have a crush on their date will automatically synchronize their physical movements during the dating process, including smiling, nodding, and moving their arms and legs. The team also found an intriguing phenomenon that women were more likely to be attracted to men who were “in sync”. The related paper was published under the title of “Biological Behavioral Synchronization as a Potential Mechanism of Human Mate Selection”.
The team took 32 college students (16 males, 16 females) and measured electrodermal activity, the sympathetic nervous system, with a wearable device, recording subtle changes in their physical metrics during dating, and Every movement of each person during the dating process, such as nodding, moving arms, moving legs, etc.
The galvanic skin activity mentioned above refers to the continuous change of the galvanic properties of the skin. Typically, it is measured as skin conductance (the process of transmitting electrical signals between two points on the skin’s surface) by applying a small constant voltage to the skin. Since the voltage remains constant, skin conductance can be calculated by measuring the current flowing through the electrodes.
Specifically, the team used the wristband Empatica E4 to extract 1200 physiological data points (sampled at 4Hz) and 3000 behavioral data points (sampled at 10Hz) for participants. Participants were able to interact naturally, and their dating room was recorded by dynamic devices to ecologically valid estimates of biobehavioral measures that occurred naturally during the dating period.
Researchers use wristbands to detect physiological signals of dating partners
After the date, participants rated the attractiveness of the date. The researchers measured the association between physiological synchronization and behavioral coordination during the date, as well as participants’ ratings of the attractiveness of the date after the date.
The experiment was conducted in three rounds, in which both men and women met in rotation. Each appointment lasts 5 minutes, for a total of 46 appointments. According to the team, “When a man and a woman are highly synchronized and coordinated on their physiological indicators on a date, their mutual favorability is also high.”
Based on relevant test results, the researchers found that within two minutes of dating, by monitoring Physiological synchronization signals between men and women when dating can predict whether they will “fall in love at first sight”. Through a series of monitoring and comparative observations of the participants, the team believes that behavioral and physiological synchronization can serve as an effective mechanism for attracting partners.
Coupling of Galvanic Skin Activity and Behavior During Dating Indicates Dating Outcomes
In addition, in the course of the research, the team also discovered an interesting phenomenon, that is, the degree of physiological synchronization between men and women is not the same as the attraction. Women were more attracted to men whose physiology was highly synchronized, although monitoring could predict whether they would be attracted to a partner on a date.
In previous studies, it was generally believed that the attractiveness of a dated person came from “static characteristics”, such as face shape, hair color, etc. And according to the results of the Hebrew University team’s paper, they argue, “people who are better at adapting their physiology and behavior to their partner during dating are more likely to be attracted to that partner.”
Research lab setup at Leiden University
The study demonstrates that co-regulation of behavior and physiology is strongly linked to dating outcomes, and that when dating partners synchronize their galvanic skin activity and dynamically adjust their behavior, they are more likely to be attracted to each other. That is, co-regulation of sympathetic and behavioral rhythms between males and females is a mechanism that promotes attractiveness.
A research team from Leiden University in the Netherlands conducted a similar study. In a 2021 paper, they found that synchronized sweating and heart rate were more important indicators of whether a date was attractive than physical movements.
They found that there was no significant link between daters’ attractiveness and imitating body language, whether in terms of smiles, direct eye contact, nods, or gestures.
Instead, they found that attractiveness can be predicted by synchronizing the heart rate and skin conductance of the dating partner, the hidden, unconscious, and difficult-to-regulate physiological indicators behind goodwill toward others. The results of the Leiden University study show that “the attractiveness of dating partners will increase or decrease synchronously with changes in their physiological indicators.”