Research shows that pacifiers disrupt infants' mimicry of facial expressions. This experiment examines whether pacifiers interfere with caretakers' ability to mimic infants' emotions. Adults saw photographs of infants with or without a pacifier. When infants had pacifiers, perceivers showed reduced EMG activity to infants' smiles. Smiles of infants using a pacifier were also rated as less happy than smiles depicted without a pacifier. The same pattern was observed for expressions of distress: adults rated infants presented with pacifiers as less sad than infants without pacifiers. We discuss deleterious effects of pacifier use for the perceiver's resonance with a child's emotions.