The age dependence of stereotyped behaviours in blind infants and preschoolers.

As part of a research programme on early intervention and family care for blind infants and preschoolers, the Bielefeld Parents' Questionnaire for Blind and Sighted Infants and Preschoolers was given to 85 parents of congenitally blind children. All 85 children (from 5 to 72 months) in the sample were totally blind and had no further serious disabilities. A comparison of five age groups of blind infants and preschoolers indicated that the repertoire of stereotyped behaviour patterns depended on age. After expanding from the first to the second year of life, the range of different stereotyped behaviours decreased from the age of 3 years up to school enrollment. The amount of stereotyped behaviours showed a similar course. Among the individual stereotyped behaviours, only the frequency of eye poking and body rocking increased from the first to the second year of life and then maintained a relatively high level across the entire preschool age range. The situational and person-specific conditions under which stereotyped behaviours could typically be observed also appeared to change with the child's age. While in the first years of life, monotony and arousal situations dominated among the elicited stereotyped behaviours, the 4- to 6-year-old blind children increasingly exhibited stereotyped behaviours in situations in which they were confronted with cognitive and concentrative demands. Various possible explanations of the age dependence of stereotyped behaviour patterns in blind infants and preschoolers are discussed.