The cries of infants of differing levels of perceived temperamental difficultness: acoustic properties and effects on listeners.

The meaning of mother perceptions of their infants' temperamental difficultness was explored in 3 ways. (1) Subjective ratings were elicited from unrelated mothers of infants (N = 45) who listened to the cries of 4-6-month-old infants perceived by their own mothers as having difficult, average, or easy temperament (N = 4 per category). Subjects rated the difficult- and average-group cries as more irritating and spoiled sounding than the easy-group cries, and more likely to be due to emotional or psychological causes. However, there were no differences in the subjects' hypothetical interventions. (2) The meaning of the difficultness designations was also tested by measuring the acoustic properties of the cries of the 12 infants using sound spectrographs. The clearest difference was that the more difficult groups showed increased amounts of pausing within and between cry sounds, which is interpreted as adding a sense of urgent demand to the cry communication. (3) The study also considered the effects of a variety of listener background, personality, and attitude variables. The listener's perception of the difficultness of her own 4-6-month, firstborn infant was not related to ratings of the cries, but her prior experience with infants and level of self-described empathy were related to the ratings. For example, the more experienced the listener, the less the easy and average infants' cries were rated as spoiled, and the more the difficult infants' cries were seen as spoiled.

Measurement of infant difficultness.

The Infant Characteristics Questionnaire (ICQ) was developed as a short, factor-analytic screening device for difficultness. Responses of 322 mothers of 4-6-month-old infants suggested that they regard the fussy, hard-to-soothe, labile infant as difficult. Mother report on the ICQ, particularly on the main fussy-difficult factor was found to have adequate reliability over time and convergence with the Carey Survey of Temperamental Characteristics, with father report on the ICQ, and, to a lower degree, with home data collected by independent observers. It was also found that mother characteristics may affect perceptions of infant difficultness: multiparous, extraverted mothers tended to rate their infants as easy.