The prototype willingness model (PWM) was designed to extend expectancy-value models of health behaviour by also including a heuristic, or social reactive pathway, to better explain health-risk behaviours in adolescents and young adults. The pathway includes prototype; i.e., images of a typical person who engages in a behaviour; and willingness to engage in behaviour.The current study describes a meta-analysis of predictive research using the PWM, and explores the role of the heuristic pathway and intentions in predicting behaviour. Eighty-one studies met inclusion criteria. Overall, the PWM was supported and explained 20.5% of the variance in behaviour. Willingness explained 4.9% of the variance in behaviour over and above intention, although intention tended to be more strongly related to behaviour than was willingness. The strength of the PWM relationships tended to vary according to the behaviour being tested, with alcohol consumption being the behaviour best explained. Age was also an important moderator, and, as expected, PWM behaviour was best accounted for within adolescent samples. Results were heterogeneous even after moderators were taken into consideration. This meta-analysis provides support for the PWM and may be used to inform future interventions that can be tailored for at-risk populations.Key Words: prototype willingness model; meta-analysis; health behaviour; health models
REASONED VERSUS REACTIVE PREDICTION 3Reasoned versus reactive prediction of behaviour: A meta-analysis of the prototype willingness model
RationaleMany illnesses and diseases are at least partly attributable to the performance or nonperformance of health-risk or health-enhancing behaviours (World Health Organization: WHO, 2009). Investigating reasons for engaging or not engaging in these behaviours is a major area of interest for health psychologists, and many theoretical models have been proposed to explain such behaviours. Models often concentrate on social-cognitive aspects of behaviour, as these aspects tend to be malleable (Conner & Norman, 1996), and indeed such expectancy-value models dominate the literature (Gerrard, Gibbons, Houlihan, Stock, & Pomery, 2008). These models assume that health-related behaviour is planned, by a process of weighing up the costs and benefits of behavioural outcomes.Expectancy-value models such as the Theory of Planned Behaviour (TPB), and its precursor the Theory of Reasoned Action (TRA) place intention as the most proximal determinant of volitional behaviour (Ajzen, 1991). The TPB and TRA have been used to predict a range of behaviours; however, these models tend to predict intention better than behaviour (Armitage & Conner, 2001), and the relatively weak relationship between intention and behaviour indicates that individuals do not always act as they intend (Sheeran, 2002).A number of dual-process models have also received attention in the literature; for example, Fuzzy Trace Theory (Rivers, Reyna, & Mills, 2008), Cognitive Experiential Self Theory (Epstein, 1985), and within ...