Interpersonal contingencies: Performance differences and cost-effectiveness.

College students pressed a telegraph key for nickels. The experimenter switched the rules every session.

Sometimes each press paid a nickel (individual). Sometimes two students shared earnings if both pressed enough (co-op). Sometimes only the higher scorer got paid (competition).

Individual and co-op kept fast pressing. Competition cut total presses almost in half.

Yet competition was the cheapest for the experimenter: fewer nickels bought each response. Students still picked individual or co-op when given the choice.

Geurts et al. (2008) moved the same token-economy logic into a rehab ward. Prize draws for clean breath tests kept smokers abstinent longer than standard care. Lab lesson: contingency works; clinic lesson: it works on life-or-death behavior.

Van Hanegem et al. (2014) repeated the alternating-treatments trick with kids who hit to escape tasks. Contingent reinforcement for compliance beat a time-based goodie bag, mirroring R’s finding that payoff rules matter more than payoff size.

Kohler et al. (1985) showed the flip side: non-contingent “practice” after self-injury did nothing. Together the three studies say the same thing: if the reinforcer isn’t tied to the response, you waste your time and your nickels.

When you design a token board, first decide if the client earns stars alone, with a peer, or against a peer. Individual or co-op keeps responding high; competition can save reinforcers but may drop motivation. Offer a choice when you can—given the option, most learners pick the sure, smaller payoff.