ROBUSTNESS OF INDIVIDUAL IDENTITY IN THE CRIES OF HUMAN INFANTS

This study investigated the possibility that one function of the human infant's cry is to convey individual identity across distance. Six-hu ndred adults, having been exposed to 30 s of an infant's crying, were asked to identify this infant on the basis of other, experimentally al tered, cries. The cries were altered naturally by rerecording across d istance in the out-of-doors, and artificially by bandpass filtering an d temporal reorganization. The individuality of cries proved remarkabl y robust to degradation: Only when frequencies were limited to the ran ge of 8 to 10 kHz was recognition performance significantly impaired. It is argued that the human infant's cry, a complex signal with multip le markers of individuality, may have among its functions the communic ation of infants' identities across distance. (C) 1994 John Wiley and Sons, Inc.