Children’s Developing Understanding of the Utility of Emotions for Cognitive and Physical Performance In popular culture, positive emotions are often portrayed as performance-enhancing (e.g., “happy students learn better”) and negative emotions as performance-impairing (e.g., “don’t let anger get the best of you). However, the relationship between emotions and performance is not always straightforward. When positive emotions become too intense, they can impair cognitive performance, and anger—despite being a negative emotion—can sometimes enhance performance. Do people’s lay theories of emotions capture this complex relationship? If so, how early in development do children grasp these nuances? Across nine preregistered experiments, we explored children’s and adults’ beliefs about the utility of emotions across different tasks. We found a developing appreciation of the impact of emotional intensity and valence on physical and cognitive performance between ages 5 and 10. These developments appear to be driven by a growing appreciation of how emotional valence and intensity affect cognitive processes, allowing children to better weigh the motivational, attentional, and energetic benefits of emotions against their potential costs to regulation and cognitive control. Our findings have implications for understanding children’s reasoning about how the mind works and for socio-emotional learning programs that teach the value of emotions. ON SITE & Zoom : https://unige.zoom.us/j/68539580478?pwd=WuWADFvTo8ySY6zRPcLy3wvVebLKKI.1 Meeting ID: 685 3958 0478 Passcode: 071247