Finally, we sought to determine whether or not play acquired via behavioral intervention would occur in the absence of
programmed reinforcement contingencies (extrinsic reinforcement). Our findings suggest that play skills acquired via
socially mediated reinforcement may have come to be automatically reinforced (intrinsically motivated). Specifically, toyplay
was reinforced with social praise and the delivery of preferred edibles during intervention phases. However, baseline
phases were conducted in a therapy room where external reinforcement for play had never been delivered and where the
person associated with reinforcer delivery (i.e., teacher) was absent. Therefore, the baseline sessions were absent the
discriminative stimuli that signaled the availability of socially mediated reinforcement. With discriminative stimuli absent