When prior knowledge overrules new evidence: Adaptive use of decision strategies and role behavioral routines

This paper focuses on behavioral routines in adaptive decision making - an issue which has fairly been neglected to date. In two successive experiments, participants worked on recurrent, multiattribute choice problems. In the first experiment, we induced routines by relying upon the human ability to adapt to situational changes by changing decision strategies. To induce strategy change, time pressure was varied as a within factor. Payoffs were manipulated so that an adaptive change in strategy led participants to maximize choice frequency for one out of three options (routine acquisition). One group was instructed to use a limited set of strategies (expected utility, elimination by aspects, lexicographic rule), the other group received no instruction. Participants of both groups adapted successfully to time constraints, resulting in preference for the intended routine option in about 65 of the choices. After a one week time lapse, participants worked on similar problems, containing the routine option. In this second experiment payoffs favoured deviation from the routine. Results showed that choices were almost perfectly calibrated to payoffs under low time pressure. However, if time pressure increased, participants were more likely to prefer the routine option, even though strategies were still used adaptively and evidence discouraged routine selection.