Synchrony
Moving in time with someone tends to increase affiliation in lab tasks; in dating, coordination may follow interest rather than create it.
Evidence: PlausiblePlausible: One study, or indirect evidence from a nearby question. This is the weakest level among the claims below.
What the research shows
Two meta-analyses of lab experiments report that doing something in time with another person, such as tapping or moving together, tends to increase affiliation and cooperation toward them, with smaller effects on mood. In one speed-dating study, pairs whose body sway was coupled in a leading-and-following way reported more interest in a long-term relationship, while swaying alike without that pattern did not predict interest; the design cannot show which came first. Deliberate copying has a mixed record: a preregistered study found no effect of mimicry on rapport. What you can take from it: an easy shared rhythm is something to notice, not to engineer, and it is never permission for touch.123
What dating marketing says it shows
A typical sales line, written for this page
A typical sales line promises: "Match her rhythm, then lead it, and she will start following you." Pages like this present synchrony as a way to create chemistry in someone else and to read it from her movements.
What doesn't follow
The lab studies measured affiliation among strangers in brief tasks, not romantic interest, and the dating result is a single correlational study, so synchrony can neither be used to create interest nor be read as proof of it in one person.
Limits
Brief, structured lab tasks; meta-analytic effects are moderated by experimenter effects and by whether synchrony was intentional, and concern prosocial outcomes. One speed-dating study, correlational, in a single setting. The mimicry null comes from a small avatar study.
Sources
Each numbered mark above opens the evidence behind that statement: the label, what it does not show and where it comes from.
Evidence: Supported with caveatsIn laboratory experiments, doing something in time with another person, such as tapping or moving together, tends to increase feelings of affiliation and cooperative behaviour toward that person.
Why this label
Several studies agree, with stated limits such as student samples or lab settings. Two meta-analyses of synchrony experiments report medium-sized effects on prosocial outcomes, and a tapping study found that closer synchrony went with higher affiliation ratings. Effects are on generic affiliation among strangers, not on romantic attraction.
What it does not show
- Meta-analytic effects shrink for some outcomes (small for positive affect) and are moderated by experimenter effects and by whether synchrony was intentional.
- Brief, structured lab tasks, not conversation or dating; sample composition not checked in full text.
- Effects concern prosociality and bonding, not romantic interest.
Who it applies to
A pattern across groups of people, not a statement about any one person.
Sources
- Mogan, R., Fischer, R., Bulbulia, J. A. (2017). To be in synchrony or not? A meta-analysis of synchrony's effects on behavior, perception, cognition and affect, Journal of Experimental Social Psychology 72, 13-20.
- Rennung, M., Göritz, A. S. (2016). Prosocial Consequences of Interpersonal Synchrony: A Meta-Analysis, Zeitschrift für Psychologie 224(3), 168-189.
- Hove, M. J., Risen, J. L. (2009). It's All in the Timing: Interpersonal Synchrony Increases Affiliation, Social Cognition 27(6), 949-960.
Evidence: PlausibleIn one speed-dating study, partners whose body sway was coupled in a leading-and-following way reported more interest in a long-term relationship, over and above rated attractiveness, while simply swaying alike did not predict interest.
Why this label
One study, or indirect evidence from a nearby question. The result shows that coordination can accompany romantic interest in a real dating setting. It is correlational and from one study, and it gives no basis for treating a partner's movement as a sign of consent or for trying to engineer synchrony.
What it does not show
- Single study; correlational, so synchrony may reflect interest rather than cause it.
- Speed-dating setting with background music; sample details not recorded here.
- Population-level finding; says nothing reliable about one person's interest, and never authorises touch.
Who it applies to
A pattern across groups of people, not a statement about any one person.
Source
- Chang, A., Kragness, H. E., Tsou, W., Bosnyak, D. J., Thiede, A., Trainor, L. J. (2020). Body sway predicts romantic interest in speed dating, Social Cognitive and Affective Neuroscience 16(1-2), 185-192.
Evidence: PlausibleMirroring someone is not a dependable way to build rapport: a preregistered virtual-reality study found no effect of avatar mimicry on rapport or trust, although an earlier study in the same paper had found higher rapport.
Why this label
One study, or indirect evidence from a nearby question. The first study (n=50) found higher rapport towards mimicking avatars, but the preregistered replication (n=40) found no effects on rapport, trust or trust behaviour. This is a single research group's pair of small studies, so the safest wording is that the effect is not dependable.
What it does not show
- Small samples; avatars in virtual reality, not live human conversation.
- Second study also tested cultural ingroup versus outgroup avatars, which may have diluted power.
- One failed replication does not show the effect is zero.
Who it applies to
Depends on the setting and the people involved.
Sources
- Hale, J., Hamilton, A. F. D. C. (2016). Testing the relationship between mimicry, trust and rapport in virtual reality conversations, Scientific Reports 6, 35295.
- Chartrand, T. L., Bargh, J. A. (1999). The chameleon effect: The perception–behavior link and social interaction, Journal of Personality and Social Psychology 76(6), 893-910.