Maternal emotional signaling: Its effect on the visual cliff behavior of 1-year-olds.

Facial expressions of emotion are not merely responses indicative of internal states, they are also stimulus patterns that regulate the behavior of others. A series of four studies indicate that, by 12 months of age, human infants seek out and use such facial expressions to disambiguate situations. The deep side of a visual cliff was adjusted to a height that produced no clear avoidance and much referencing of the mother. If a mother posed joy or interest while her infant referenced, most infants crossed the deep side. If a mother posed fear or anger, very few infants crossed. If a mother posed sadness, an intermediate number crossed. These findings are not interpretable as a discrepancy reaction to an odd pose: in the absence of any depth whatsoever, few infants referenced the mother and those who did while the mother was posing fear hesitated but crossed nonetheless. The latter finding suggests that facial expressions regulate behavior most clearly in contexts of uncertainty.