Learning increasingly happens online. We find that loading lags of just 1-2 seconds can disrupt learning. Across two online learning platforms and more than 80,000 learners, loading microdelays were tied to decreased engagement and poorer learning outcomes.
Why do we reach for another cup of coffee? When we asked people, they said it's usually out of tiredness. When we examined their behavior over the course of a week, we found that habit strength matched or exceeded fatigue in predicting coffee drinking. People overlook habits in explanations of behavior.
Conventional wisdom suggests that habits form best in response to variable rewards rather than consistent ones. We challenge this view using large scale field data (N > 1M posts) and six pre-registered experiments. In the field and in the lab, consistent rewards promote long-term persistence more effectively than variable rewards. These findings question long-standing assumptions and highlight the role of predictability in habit learning.
Can talking to AI change how we treat other people? Across two preregistered experiments, people judged another person’s work more harshly after collaborating with a partner presented as AI rather than human. These findings suggest that the effects of human–AI interaction can extend into subsequent interactions with other people.
Small practical barriers can have large consequences for public health. People living farther from vaccination sites were less likely to get vaccinated (Study 1), and vaccine uptake increased when sites opened nearby (Study 2). Together, these findings highlight reducing friction as a practical tool for promoting vaccination, alongside efforts to address beliefs and intentions.