--- - |2 Abstract Physiological responses can reveal emotional states that individuals are unwilling to admit to others. Here, we studied what blushing reveals about the emotional states of narcissistic children. Narcissistic children (i.e., those high on the personality trait of narcissism) have a pervasive sense of grandiosity. We theorized that narcissistic children are so invested in their sense of grandiosity that even modest praise can make them feel depreciated. Because narcissistic children may not admit this feeling to others, we measured their physiological blushing: an involuntary reddening of the face that occurs when individuals anticipate being depreciated. Unlike other emotional expressions, blushing cannot be faked. Children (N = 105, ages 7–12) completed the Childhood Narcissism Scale and were then invited to sing a song on stage. They were randomly assigned to receive inflated praise (e.g., “You sang incredibly well!”), modest praise (“You sang well!”), or no praise for their performance. Blushing was recorded using photoplethysmography and temperature sensing. Afterward, children were asked how much they thought they had blushed. As predicted, narcissistic children—unlike nonnarcissistic children—blushed when they received modest praise, not when they received inflated praise. Specifically, they showed increased blood volume pulse (i.e., fast changes in blood volume with each heartbeat). Strikingly, when asked, narcissistic children denied blushing, perhaps to hide their vulnerabilities. Thus, blushing revealed social‐evaluative concerns that narcissistic children wished to keep private. - Psychophysiology, Volume 55, Issue 10, October 2018.