Related Experiment Videos
The role of verbal behavior in human learning: infant performance on fixed-interval schedules
Insights
Infants under one year old showed animal-like responses to fixed-interval schedules, developing a scalloped pattern of behavior. This suggests early development, not verbal skills, influences schedule performance in young humans.
Area of Science:
- Behavioral Psychology
- Developmental Psychology
- Operant Conditioning
Background:
- Human operant behavior on fixed-interval schedules typically differs from animal behavior due to complex cognitive processes.
- Previous research suggests verbal behavior significantly influences schedule-controlled responding in older humans.
Purpose of the Study:
- To investigate the operant behavior of infants on fixed-interval (FI) schedules.
- To compare infant responding to established patterns in animals and older humans.
- To explore the developmental trajectory of schedule-controlled behavior.
Main Methods:
- Two human infants (<1 year old) were exposed to fixed-interval schedules (10-50 seconds) where touching a cylinder yielded music or food.
- Response patterns, sensitivity to schedule parameters, and interresponse times were analyzed.
- Behavioral data were compared across different schedule values and to existing literature on animals and older children.
Main Results:
- Infant behavior initially showed negatively accelerated responding, transitioning to a characteristic 'scalloped' pattern (post-reinforcement pause followed by acceleration).
- This scalloped pattern emerged across all tested fixed-interval schedule values.
- Post-reinforcement pause duration increased with schedule value, while running rate decreased, mirroring animal responding.
Conclusions:
- Infants' performance on fixed-interval schedules closely resembles that of animals, differing significantly from older children and adults.
- The findings support the hypothesis that the development of verbal behavior in humans leads to distinct patterns of schedule-controlled responding.
- Early behavioral development, rather than verbal mediation, appears to govern the operant behavior of very young infants on interval schedules.
Abstract:
The performances of two infants less than one year old were investigated on fixed-interval schedules. When the infants touched a cylinder either music or food was presented according to fixed-interval schedules ranging in value from 10 to 50 seconds. With respect to two principal criteria, namely, pattern of responding and sensitivity to the schedule parameter, the subjects' behavior closely resembled that of animals but differed markedly from that of older children and adults. Negatively accelerated responding in the course of the fixed interval in the early sessions gave way to a scalloped pattern, consisting of a pause after reinforcement followed by an accelerated response rate. This scalloped pattern was the final form of responding on all schedule values. Analysis of data after performance had stabilized showed that postreinforcement pause was a negatively accelerated increasing function, and running rate (calculated after excluding the postreinforcement pause) was a declining function, of schedule value. On each schedule, the durations of mean successive interresponse times declined in the course of the fixed interval and were directly related to schedule value. The results supported Lowe's (1979) suggestion that verbal behavior may be responsible for major differences in the schedule performance of older humans and animals.