Couples whose movements aren't in synch may be falling out of synch.
If you and your significant other have similar movements when you're together, that's a sign of a healthy relationship.
"A more positive interaction will show increased coordination (also often called behavior synchrony or entrainment) and vice versa," Narayanan, a USC professor of computer science, linguistics, and psychology, told Tech Insider.
"So a friendly interaction would show more coordination than one with conflict."
How you and your partner move your heads while talking can speak to your relationship's healthiness.
"How people move their heads together tells us something about the richness of their interactions," Narayanan explained in an interview with Tech Insider.
A study Narayanan was a co-author of found that "the more animated the couple, the more likely they are to exhibit similar motion events."
The study looked at how wives and husbands moved their heads when one was discussing an issue in therapy.
The researchers assigned four codes that measured the emotional component of the relationship — acceptance, blame, positive, and negative. It found that similar head movements between couples were correlated with healthier relationship codes, like positive and acceptance.
Couples in positive relationships tend to speak similarly.
Turns out there's some merit to the idea that people who jive well together tend to speak similarly.
Couples exhibiting positive interactions tend to speak with the same intonation and rhythm, according to another USC study.
"When applied to married couple interactions, it was shown that interactions rated by experts to be more positive had greater similarity than ones rated to be negative," Narayanan, an author on the study, said.
It's not a good sign if either person uses "I" versus "we" when talking about the relationship.
A UCLA and University of Washington study looked at 134 distressed and 48 nondistressed couples and found that the different subsets used pronouns at different rates. It found that individuals in healthy relationships tend to think about their relationship as a unit, which is reflected in the way they speak (for example, using "we" versus "I").
A study Narayanan co-authored found a similar trend when he had a computer analyze the audio recordings of couples' interactions.
"'You' is considered more of a blaming word" than we, Narayanan explained.
Bottom line: couples in healthy relationships show greater coordination than ones in unhealthy relationships.
Whether it's the way you move, speak, or talk about the relationship, coordination matters. This is called "entrainment," Narayanan said. It's the concept that people in happy relations exhibit similar behaviors.
"In sum, humans seem to have a tendency toward greater behavior coordination when exhibiting and reflecting positivity," Narayanan said.
