Are children from “Eastern” cultures less emotionally expressive and reactive than children from “Western” cultures? To answer this, we used a multi‐level and multi‐contextual approach to understand variations in emotion displays and cortisol reactivity among preschoolers living in China and the United States. One hundred two preschoolers from China (
Chinese preschoolers displayed lower overall positive and negative expressions relative to their US counterparts without considering situational contexts. Chinese preschoolers displayed similar levels of emotion expressions as their US counterparts during an achievement‐related challenge salient to their social‐cultural environment. Chinese preschoolers are particularly responsive to achievement‐related challenges, relative to other emotion‐challenging situations that are less culturally salient. No cortisol increase was observed in any of the emotion‐challenging paradigms among US preschoolers. Children's emotion expression and biological reactivity may be most responsive to challenges relevant to their socio‐cultural environments.