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Five- and 12-month-old Japanese and American infants participated in a nonpainful arm restraint procedure. Facial responses were scored with an anatomically based coding system (Baby FACS, an adaptation for infants of Ekman and Friesen's, 1978, Facial Action Coding System, or FACS). Nonfacial body activity (struggling) and negative vocalizations also were scored
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Camras et al. (1992) studied this question.
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