Conditional or unconditional? The effects of implementation intentions on driver behavior.

Implementation intentions (if-then plans) exert conditional effects on behavior, meaning that their ability to change behavior is conditional upon encountering the critical situation specified in the if component of the plan. In the present study, we tested whether implementation intentions can exert unconditional effects on behavior. Consistent with the process of operant generalization, we hypothesized that implementation intentions would change behavior, not only in situations that are contextually identical to those specified in the if component but also in contextually similar situations. Implementation intentions were not expected to generate behavior-change in contextually different situations to those specified. Participants (N = 139) completed questionnaires measuring speeding behavior and motivation to speed. Experimental participants then specified implementation intentions to avoid speeding in critical situations that were contextually identical, similar, or different to those subsequently encountered on a driving simulator. Control participants received educational information about the risks of speeding. All participants then drove on a driving simulator. Consistent with the hypotheses participants in both the contextually identical and similar conditions exceeded the speed limit less frequently than did controls. There was no difference in speeding behavior between the contextually different and control conditions. Implications of the findings for behavior-change are discussed.

Evidence that implementation intentions reduce drivers' speeding behavior: testing a new intervention to change driver behavior.

Implementation intentions have the potential to break unwanted habits and help individuals behave in line with their goal intentions. We tested the effects of implementation intentions in the context of drivers' speeding behavior. A randomized controlled design was used. Speeding behavior, goal intentions and theoretically derived motivational pre-cursors of goal intentions were measured at both baseline and follow-up (one month later) using self-report questionnaires. Immediately following the baseline questionnaire, the experimental (intervention) group (N=117) specified implementation intentions using a volitional help sheet, which required the participants to link critical situations in which they were tempted to speed with goal-directed responses to resist the temptation. The control group (N=126) instead received general information about the risks of speeding. In support of the hypotheses, the experimental group reported exceeding the speed limit significantly less often at follow-up than did the control group. This effect was specific to 'inclined abstainers' (i.e., participants who reported speeding more than they intended to at baseline and were therefore motivated to reduce their speeding) and could not be attributed to any changes in goal intentions to speed or any other measured motivational construct. Also in line with the hypotheses, implementation intentions attenuated the past-subsequent speeding behavior relationship and augmented the goal intention - subsequent speeding behavior relationship. The findings imply that implementation intentions are effective at reducing speeding and that they do so by weakening the effect of habit, thereby helping drivers to behave in accordance with their existing goal intentions. The volitional help sheet used in this study is an effective tool for promoting implementation intentions to reduce speeding.

Testing the bi-dimensional effects of attitudes on behavioural intentions and subsequent behaviour.

Attitudes are typically treated as unidimensional predictors of both behavioural intentions and subsequent behaviour. On the basis of previous research showing that attitudes comprise two independent, positive and negative dimensions, we hypothesized that attitudes would be bi-dimensional predictors of both behavioural intentions and subsequent behaviour. We focused on health-risk behaviours. We therefore also hypothesized that the positive dimension of attitude (evaluations of positive behavioural outcomes) would better predict both behavioural intentions and subsequent behaviour than would the negative dimension, consistent with the positivity bias/offset principle. In Study 1 (cross sectional design), N = 109 university students completed questionnaire measures of their intentions to binge-drink and the positive and negative dimensions of attitude. Consistent with the hypotheses, both attitude dimensions independently predicted behavioural intentions and the positive dimension was a significantly better predictor than was the negative dimension. The same pattern of findings emerged in Study 2 (cross sectional design; N = 186 university students) when we predicted intentions to binge-drink, smoke and consume a high-fat diet. Similarly, in Study 3 (prospective design; N = 1,232 speed limit offenders), both the positive and negative dimensions of attitude predicted subsequent (6-month post-baseline) speeding behaviour on two different road types and the positive dimension was the better predictor. The implications for understanding the motivation of behaviour and the development of behaviour-change interventions are discussed.