AbstractLaboratory and field research has reported that the appearance of infants causes observers to smile. The current study examined whether this smiling response is modulated by the observer's task and evaluative dimension. Thirty‐nine young nulliparous women were asked to rate the cuteness or beauty levels of 6‐month‐old infants' faces using a 7‐point scale in different blocks. Facial electromyograms (EMGs) were recorded of participants' facial muscles related to both smiling (the zygomaticus major [ZM] and orbicularis oculi [OO]) and frowning (the corrugator supercilii [CS]). The results showed that cuteness and beauty ratings were highly correlated with each other (r = .90), indicating that these evaluations were based on similar attractiveness‐related physical features. Facial EMG responses on the smiling muscle sites, ZM and OO, increased significantly from the baseline when participants rated the faces' cuteness, and the responses were larger than when participants rated the faces' beauty. CS activity was not found to have any effect. The perceived cuteness level of the infant faces did not affect the facial EMG responses. Moreover, the magnitude of the smiling response was shown to be much smaller than that associated with voluntary smiling. These findings suggest that facial expressions while viewing infant faces do not exhibit a fixed pattern but are modulated by observers' tasks and that considering cuteness, which is based on more affective evaluations than beauty, can enhance smiling responses.