A parametric variation of delayed reinforcement in infants.
Babies only a few months old learn from praise that comes up to five seconds late, so brief delays are fine in early language work.
01Research in Context
What this study did
The team worked with babies who were 2 to 6 months old.
They used a simple ABAB design.
In some phases the baby’s coo or babble got a smile and gentle touch after 3 s or 5 s.
In other phases the same sounds got no reaction.
No lights, buzzers, or signals warned the baby that praise was coming.
What they found
Both the 3-second and the 5-second delayed praise raised the babies’ sounds.
When the praise stopped, the sounds dropped.
When the praise returned, the sounds came back.
The babies learned even though the reward was late and unannounced.
How this fits with other research
Pelaez et al. (2011) got the same vocal boost, but they used immediate imitation instead of delayed praise.
The two studies line up: any social consequence that follows the sound can work.
Neimy et al. (2020) moved the same immediate-imitation trick into homes of babies at risk for autism and still saw big gains.
Together the chain shows the contingency matters more than the clock.
Why it matters
You can reinforce early babble even if you are busy and the reward comes a few seconds late.
Do not wait for perfect timing; a calm “good job” or gentle pat within five seconds still teaches the baby that sounds bring people closer.
Use this when you coach new parents or run infant language sessions.
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02At a glance
03Original abstract
This study is an exploration of the parameters of delayed reinforcement with 6 infants (2 to 6 months old) in two experiments using single-subject repeated-reversal designs. In Experiment 1, unsignaled 3-s delayed reinforcement was used to increase infant vocalization rate when compared to a differential-reinforcement-of-other-than-vocalization condition and a yoked, no-contingency comparison condition. In Experiment 2, unsignaled 5-s delayed reinforcement was used to increase infant vocalization rate when compared to an alternating-treatments comparison condition. The alternating-treatments comparison consisted of 3-min components of differential reinforcement of other behavior and 3-min components of a nontreatment baseline. Successful conditioning was obtained in both experiments. These results contrast with those of previous infancy researchers who did not obtained conditioning with delays of 3 s and who attributed their findings to the limitations of the infant's memory capacity. We present an alternative conceptual framework and methodology for the analysis of delayed reinforcement in infants.
Journal of the experimental analysis of behavior, 1993 · doi:10.1901/jeab.1993.60-515