Substitution effects in a generalized token economy with pigeons

Abstract

Pigeons made repeated choices between earning and exchanging reinforcer-specific tokens (green tokens exchangeable for food, red tokens exchangeable for water) and reinforcer-general tokens (white tokens exchangeable for food or water) in a closed token economy. Food and green food tokens could be earned on one panel; water and red water tokens could be earned on a second panel; white generalized tokens could be earned on either panel. Responses on one key produced tokens according to a fixed-ratio schedule, whereas responses on a second key produced exchange periods, during which all previously earned tokens could be exchanged for the appropriate commodity. Most conditions were conducted in a closed economy, and pigeons distributed their token allocation in ways that permitted food and water consumption. When the price of all tokens was equal and low, most pigeons preferred the generalized tokens. When token-production prices were manipulated, pigeons reduced production of the tokens that increased in price while increasing production of the generalized tokens that remained at a fixed price. The latter is consistent with a substitution effect: Generalized tokens increased and were exchanged for the more expensive reinforcer. When food and water were made freely available outside the session, token production and exchange was sharply reduced but was not eliminated, even in conditions when it no longer produced tokens. The results join with other recent data in showing sustained generalized functions of token reinforcers, and demonstrate the utility of token-economic methods for assessing demand for and substitution among multiple commodities in a laboratory context.

Quantity–quality trade-off in the acquisition of token preference by capuchin monkeys ( Sapajus spp.)

“…The current findings extend previous observations that capuchins seek variety in their food choices [32] and preferred a token allowing them to choose among a variety of low-preferred foods rather than a token associated with multiple units of a high-preferred food [26]. Similar findings were also obtained in pigeons that preferred to earn tokens exchangeable for both food and water over tokens exchangeable for either of the two goods [33] (see also Russell et al [34] for comparable findings in children).…”

Token reinforcement: Translational research and application

“…The cost of producing the specific or generalized tokens was always the same, yet the pigeons produced disproportionately more generalized than specific tokens. Together with the results of a more recent study with the same subjects and apparatus (Andrade & Hackenberg, ), pigeons preferred generalized to specific tokens in 32 of 40 conditions in which both options were available at equal costs.…”