A functional analysis of finger sucking in children.

In this investigation, the authors experimentally assessed the functions of finger sucking for 3 typically developing children ages 6, 7, and 14. In Experiment 1, a parent-conducted functional analysis, completed in each child's natural environment, showed that each of the children's finger sucking was most likely to occur when the child was alone, suggesting that the behaviors were maintained by automatic reinforcement. Experiment 2 involved assessing the nature of the sensory stimulation that maintained finger sucking by attenuating the sensory stimulation to the fingers via the use of Band-Aids and attenuating the sensory stimulation to the mouth with a mild numbing agent for 2 of the 3 children. For the 3rd child, mouthing objects were made available noncontingently to determine whether access to such items would result in low levels of finger sucking, suggesting reinforcer substitutability. Results of these analyses suggested that finger sucking was maintained by both oral and digital stimulation for 2 children and by oral stimulation for the 3rd.