Confidence is contagious, scientists find
The findings suggest that people update their sense of how confident they should feel using signals from both their own performance and the confidence expressed by others.
Feelings of confidence and uncertainty may not be as private as we think. New research by Birkbeck, University of London published in Current Biology suggests that simply interacting with a confident or uncertain person can fundamentally shift how confident we feel, even after they are no longer around.
Across multiple experiments involving more than 200 participants, volunteers made challenging perceptual judgements and rated how confident they were in each decision. Participants made decisions either alone or alongside a partner. While participants believed this ‘partner’ was another person they were interacting with, in reality the partner’s behaviour was controlled by an artificial algorithm, designed to respond with either consistently high or low confidence.
The results revealed a striking pattern: people adjusted their own confidence to match their partner’s. When paired with a confident partner, they became more confident in their own judgments. When paired with an uncertain partner, their confidence dropped. Crucially, the effect persisted even when the partner disappeared. When participants returned to making decisions alone, those who had worked with a confident partner remained more confident, while those who had worked with an uncertain partner continued to express lower confidence. The interaction appeared to alter not just how people communicated confidence publicly, but how they privately experienced it.
Dr Daniel Yon, Reader (Associate Professor) in Cognitive Neuroscience and author of the study, said:
“We usually think feelings of confidence or uncertainty come from inside our own heads. But in these experiments, we show that confidence and uncertainty can transmit from one mind to another. People interacting with confident partners become more confident, while those interacting with uncertain partners become more uncertain. Importantly, this effect persists even when the partner disappears - suggesting a deeper change in how we really feel and what we think about ourselves.”
The research challenges the common assumption that confidence is generated purely by internal reflection and what’s happening inside our own heads. Instead, it suggests that our brains learn about how confident we should feel partly by absorbing signals from the people around us. The team used computational modelling to show how this might occur. The findings suggest that people update their sense of how confident they should feel using signals from both their own performance and the confidence expressed by others.
The findings may help explain why different social groups appear to display distinct cultures of confidence. Previous research has found that men report higher confidence than women, politicians communicate greater certainty than scientists, and financial traders seem more confident than the rest of the general population. When highly confident individuals cluster together, their certainty may amplify through mutual reinforcement, potentially contributing to groupthink or polarised decision-making.
Dr Daniel Yon added:
“If confidence can spread through social interaction, it may be possible to reshape our own confidence levels by diversifying who we spend time with. Spending time with more self-assured peers could boost our certainty, while interacting with more cautious voices might encourage humility and reduce overconfidence.”
The researchers caution that further work is needed to understand how long-lasting these socially induced changes are and whether they operate over the timescales required to shape broader cultural norms. But the findings suggest that the adage ‘you are the average of the ten people you spend the most time with’ may reflect real processes unfolding in the mind and brain.
This research was funded by The Leverhulme Trust.