Smiling, yawning and gesturing: why we unconsciously imitate one another
By copying each other’s non-verbal behaviour, we gain access to what others think and feel. In psychology, this is known as mimicry. As part of her PhD research, cognitive psychologist Fabiola Diana investigated this phenomenon in social interactions between humans and robots.
Humans and animals are constantly interacting with one another, often in subtle ways we barely notice. One such way is that we unconsciously mirror each other’s non-verbal signals—this is what psychologists call mimicry. It serves an important function: to survive, we need to cooperate and attune to one another.
Mimicry can be visible—for instance, smiling when you see someone else smile—but it can also be invisible. Our bodies may synchronise in less obvious ways, such as aligning heart rates or pupil size. For a long time, mimicry was thought to function purely as a kind of “social glue”, fostering liking, cooperation and connection.
While this idea is plausible, it is not the full story, argues cognitive psychologist Fabiola Diana in her recently published thesis. She explored the function of mimicry by reviewing existing studies and conducting her own experiments. Her findings suggest that our tendency to mirror others helps us better predict our environment, including by improving our ability to attune to others’ positive and negative emotions.
In this video, Diana explains how this works.
On 20 March 2026, Fabiola Diana defended her thesis Interactional Beings: The power of automatic mimicry and non-verbal cues in shaping human-human and human-robot naturalistic interactions.