Christopher J. Armitage

Social cognition models and health behaviour: A structured review

Abstract A number of social cognition models have been developed to account for socio-demographic variations in health behaviour. This paper distinguishes between: (a) motivational, (b) behavioural enaction, and (c) multi-stage models of health behaviour. The models are evaluated in terms of advancement of existing knowledge and - where appropriate - predictive utility. Common themes that appear within- and between- these categories are discussed, with consideration of ways in which theory may be advanced by future research. Each approach has associated strengths and weaknesses, suggesting that a “consensus” approach to the study of health behaviour may prove fruitful. Identification of the key constructs across different model types would allow coherent integration and promote further understanding of the psycho-social determinants of health behaviour.

The theory of planned behaviour: Assessment of predictive validity and ?perceived control?

The theory of planned behaviour (TPB) has received considerable attention in the literature. However, there have been few attempts to assess the proposed causal links between beliefs, attitudes, intentions and behaviour. The present study was designed to assess the predictive validity and causal ordering of TPB constructs over a 3-month period. Findings indicated good internal and test-retest reliability of assessed components; evidence for a distinction between two processes of perceived behavioural control (self-efficacy and perceived control); support for inclusion of self-identity into the model; and predictive validity of the TPB over 3 months. Perhaps more importantly, there was some evidence to support causal ordering between predicted TPB variables. In particular, cross-lagged panel correlation analysis supported the causal impact of self-efficacy on intention. The present study supports the use of the TPB as a reliable predictor of intentions and behaviour over time. It also highlights the need for further research on the relationship between attitudes, perceived behavioural control and their underlying beliefs.

Can the theory of planned behavior predict the maintenance of physical activity

This study tested the ability of the theory of planned behavior to predict actual participation in physical activity and explored the development of activity habits in a 12-week longitudinal study. People enrolling in a gymnasium (N = 94) completed standard theory of planned behavior measures at baseline and follow-up; behavior was monitored objectively in the intervening period. The data were analyzed by using both standard and repeatable events survival analysis. Results showed that (a) perceived behavioral control was significantly predictive of intentions and actual behavior, (b) stable exercise habits developed in the first 5 weeks of the study, and (c) successful prior performance enhanced perceptions of behavioral control. The implications for developing theory-based interventions that promote the maintenance of health behavior are discussed.

Attitudinal Ambivalence: A Test of Three Key Hypotheses

This article reports two studies designed to test the hypotheses that lower levels of attitudinal ambivalence are associated with attitudes that are more predictive of behavior, more stable over time, and less pliable. Study 1 (n = 346) employed a prospective design to test the effects of ambivalence on attitude-intention-behavior relationships. Findings indicated that less ambivalent attitudes were more predictive of subsequent behavioral intentions and behavior but were unrelated to attitude stability. Study 2 (n = 344) used a simple pre-post experimental design and showed that ambivalent attitudes were more pliable in the face of a persuasive communication. The findings are discussed in relation to future research into the bidimensional conceptualization of attitudes.

Evidence That Implementation Intentions Reduce Dietary Fat Intake: A Randomized Trial

This study evaluates the effectiveness of an intervention based on the concept of implementation intentions for reducing dietary fat intake. Participants (n=264) completed questionnaires on their motivation to eat a low-fat diet before being randomized to either an experimental condition, which required them to form an implementation intention, or a control condition. Results showed that, after 1 month, fat intake, saturated fat intake, and the proportion of energy derived from fat decreased significantly in the experimental group but not in the control group. This difference could not be explained by differences in motivation between the 2 groups. The findings are discussed in relation to the use of implementation intentions instead of tailored interventions to change behavior in general populations.

Temporal stability as a moderator of relationships in the Theory of Planned Behaviour.

Temporal stability of behavioural intentions and perceived behavioural control (PBC) within the Theory of Planned Behaviour were examined as moderators of the cognition-behaviour relationships in two studies. Study 1 (N = 201) examined attendance at health screening appointment (infrequently performed behaviour) using an objective measure of attendance. The impact of intentions and past behaviour on behaviour was moderated by intention stability. In addition, stable intentions were more strongly related to attitudes and past behaviour. Study 2 (N = 407) examined eating a low-fat diet (frequently performed behaviour) using a self-report measure of behaviour. The impact of intentions on behaviour was moderated by intention stability, while the impact of PBC and past behaviour on behaviour was moderated by PBC stability. Stable intentions were more strongly related to attitudes, subjective norms and PBC. Stable PBC was more strongly related to attitudes and past behaviour. The discussion considers the implications of the findings for furthering the understanding of the proximal determinants of behaviour and emphasizes the importance of temporal stability as a key measure of the strength of intentions and PBC.

Can the Theory of Planned Behaviour mediate the effects of age, gender and multidimensional health locus of control?

OBJECTIVES: The present paper reports two studies designed to test the ability of the theory of planned behaviour (TPB) to mediate the effects of age, gender and multidimensional health locus of control (MHLC) on behavioural intentions and behaviour. DESIGN: Two studies are reported. Study 1 (N = 124) employed a cross-sectional design and examined three self-reported health-related behaviours: safe sex (condom use), binge drinking and drink-driving. Study 2 (N = 201) employed a prospective design and examined actual attendance at health screening. METHODS: Respondents completed questionnaires containing measures of MHLC and TPB. The data were analysed using a combination of bivariate correlations and hierarchical multiple regression. RESULTS: Study 1 showed that the TPB was a superior predictor of health-related behavioural intentions than both demographic variables and MHLC. Study 2 corroborated the findings of Study 1, and showed that TPB variables were useful predictors of actual behaviour, although the TPB failed to fully mediate the effects of gender on screening attendance. CONCLUSIONS: Whilst the TPB accounted for significant proportions of the variance in health-related behavioural intentions and behaviour, it failed to completely mediate the effects of demographic variables. Future work is required to identify social cognitive variables that will fully mediate the effects of demographics.

Predictive validity of the theory of planned behaviour: the role of questionnaire format and social desirability

The present study was designed to assess the predictive validity of a theory of planned behaviour extended to include self-identity, in the context of health-related food choice. Following criticism of the use of questionnaires in social cognitive research, the impact of questionnaire format (random vs structured) and social desirability on questionnaire responses was assessed. Findings indicated that intention was the principal determinant of food choice; attitude, subjective norm and self-identity were independently predictive of intention. There was only weak evidence to suggest effects of social desirability or questionnaire format on component relationships. The present study indicates that the impact of questionnaire format and social desirability on models such as the theory of planned behaviour is minimal, and that such models are robust predictors of food choice. Copyright

Comparing implementation intention interventions in relation to young adults' intake of fruit and vegetables

This study tests whether the effectiveness of implementation intention-based interventions to increase fruit and vegetable intake in a young adult population can be enhanced using additional pre-intervention instructions and alternative formats; namely, an ‘if-then’ implementation intention versus a more general, ‘global’ plan that does not explicitly link a situational cue with a goal-directed response. Participants (N = 557) completed pre-test measures of planning, motivation and behaviour with respect to increasing their fruit and vegetable intake before being randomised to a 3 (intervention format: control vs. ‘if-then’ vs. ‘global’ implementation intentions) × 2 (pre-intervention instruction vs. no pre-intervention instruction) between-participants design. Results revealed a significant intervention format by time interaction, such that intake significantly increased by 0.50 portions in the if-then format condition compared with 0.31 in the global format and 0.01 in the control condition. These results suggest that ‘if-then’ manipulations are superior in promoting behaviour change in an applied setting. The use of pre-intervention instructions had no additional effect on behaviour, providing evidence for the efficacy of implementation intentions even when experimenter demand is reduced. Evidence is also presented to suggest that reported increases in intake are not related to demand characteristics.

Is there utility in the transtheoretical model

OBJECTIVES The transtheoretical model is arguably the dominant model of health behaviour change, having received unprecedented research attention, yet it has simultaneously attracted exceptional criticism. However, the criticisms have been directed almost exclusively at the stages of change, just one of fourteen components of the transtheoretical model, which may have diverted attention away from more fruitful avenues of research based on the model. DESIGN AND METHODS Narrative review. RESULTS The evidence would suggest some flaws in the concept of stages of change as currently articulated in the transtheoretical model. On a conceptual level, even studies incorporating the five stages of change point to a model that better fits Gollwitzer (1993) and Heckhausens (1991) idea of a motivational phase followed by a volitional phase. Potentially the processes of change components of the transtheoretical model may actually prove the most useful, yet have been under-researched, at least experimentally. Three studies that successfully utilise the processes of change to reduce alcohol consumption, encourage smoking cessation and increase physical activity are described. CONCLUSIONS Elements of the transtheoretical model offer promise in developing effective health behaviour change interventions, but the question arises as to whether extracting these elements undermines completely the idea of a transtheoretical model.