(PhysOrg.com) -- Two experiments showed that having just a few things in common like a favorite author or musician was enough to make someone feel the stress and anxiety that a new acquaintance was suffering. The research shows how inclined people are to form close bonds.
When something is wrong with my baby
Something is wrong with me.
And if I know she's worried
Then I would feel that same misery.
With those four lines and a soulful melody, the rhythm and blues duo Sam and Dave summed up on a 1967 album what social scientists have since proven in several controlled laboratory experiments: When the person we love hurts, we hurt too.
But how intense is our emotional and physiological connection to someone we've just met? Can a stranger's stress make us anxious? And can a new acquaintance really make our hearts go pitter-patter?
Turns out they can, say Stanford psychologists.
In a set of experiments, the researchers found that when two people share just a few things in common, one can take on the feelings and physical reactions of the other who has been placed in an uncomfortable situation.
Their findings are slated for publication in an upcoming edition of the Journal of Experimental Social Psychology.
"When people have longstanding relationships, they have shared experiences and overlapping social networks," said Greg Walton, an assistant professor of psychology. "But we found that even when you strip those things away and create a sense of social connection in a lab with a five-minute conversation, that's sufficient to build a relationship where you care about someone."
In the first experiment, 70 women filled out a questionnaire asking them to list their birthplace and a few of their favorite things such as books, movies, musicians and travel destinations.
Each woman was later introduced to a confederate a person working for the researchers but posing as a fellow test subject. In a brief conversation with the test subject, the confederate pretended to have a few things in common with some of the women but nothing in common with the others.
The women in the first group were made to feel like they just met someone who shared an interest in something rare or unusual, like an esoteric author or an underground rock band.
The confederate was told that her role in the study was to memorize and deliver a speech on neurophysiology to a panel of judges. As the participant watched, the confederate acted anxious and nervous, saying things like "I'm really bad at giving speeches" and asking if she would be evaluated on her performance.
"We had the confederate act really freaked out," said David Cwir, a doctoral candidate at the University of Waterloo and lead author of the paper.
At the same time, the test subjects answered questionnaires to gauge how stressed they felt at the moment.
The test subjects who believed they had three things in common with the confederate and felt a sense of kinship with her reported a 28 percent increase in stress over the subjects who had no shared interests with the imposter.
"The test subjects literally incorporated the feelings of the confederate into their own feelings," Cwir said. "Just by finding out they shared a few things in common was enough to create this psychological and emotional merging."
The second experiment was staged in the same way, but included 45 men and women. Instead of having the confederate prepare a stressful speech, she ran in place for three minutes while the test subjects sat in a chair and watched.
After the exercise routine left the confederate sweaty and breathless, the participants had their own vital signs measured. Those who believed they had some interests in common with the confederate had more than a 5 percent increase in their heart rates. And their blood pressure went up almost 9 percent from the start of the study.
Heart rates hardly budged among those who felt no connection to the confederate, and their blood pressure rose only about 4 percent.
"It is surprising that we found these reactions happening between strangers," said Priyanka Carr, a doctoral candidate at Stanford who conducted the second experiment. "But it shows that we're built to connect with other people. Our selves are not isolated from everyone around us. We're meant to have relationships, to feel what our partners feel."
Explore further: What makes a good horror movie?