Effects of implementation intentions on the actual performance of new environmentally friendly behaviours - Results of two field experiments

In the context of two environmentally related behaviours (using a new bus route and shopping in a bio-shop) the implications of Gollwitzer's concept of implementation intention for Ajzenz's theory of planned behaviour are studied. Results of both studies supported the assumption that furnishing a goal intention with an additional implementation intention significantly increases the likelihood of actually performing the intended new behaviour. In the second study, the implementation intention intervention is combined with receiving a small vs higher monetary incentive. Receiving the higher incentive has similar behavioural effects to forming an implementation intention, whereas combining both interventions does not result in a stronger behavioural reaction. These results indicate that the behavioural effect of a higher monetary incentive might relay a similar volitional process to that of the implementation intention. Furthermore, in both studies there is some empirical evidence that both interventions suppress the impact of competitive habits. (C) 2002 Elsevier Science Ltd. All rights reserved.