Development and Demonstration of Paired Stimulus Preference Assessment and Embedded Reinforcer Validation with Adult Gorillas

Abstract We examined the use of a paired stimulus preference assessment (PSPA) to identify preferred items of two adult male western lowland gorillas (Gorilla gorilla gorilla). Subsequently, we validated the most preferred items as reinforcers by assessing the gorillas’ participation in cooperative care-related daily training (also known as husbandry training) where these items were used. Frequency data were collected for the number of times each item was selected during preference assessments and the number of correct short-latency responses from the gorillas during the validation. Results indicate that items identified as preferred in the PSPA functioned as reinforcers for previously learned behaviors during training sessions. We describe the use of the PSPA as an efficient means of identifying potential reinforcers for husbandry training in the zoological setting and demonstrate an embedded methodology to validate the value of items selected frequently in a PSPA.