Broaden-and-build

The broaden-and-build theory of positive emotions suggests that positive emotions (viz. enjoyment/happiness/joy, and perhaps interest/anticipation) broaden one's awareness and encourage novel, varied, and exploratory thoughts and actions. Over time, this broadened behavioral repertoire builds skills and resources. For example, curiosity about a landscape becomes valuable navigational knowledge; pleasant interactions with a stranger become a supportive friendship; aimless physical play becomes exercise and physical excellence.