The effect of self‐identity alongside perceived importance within the theory of planned behaviour

Self‐identity often predicts behavioural intentions after standard theory of planned behaviour (TPB) components are accounted for. However, it has been claimed this is due to conceptual similarity between self‐identity and perceived importance of the behaviour. We examined this claim within the context of recycling food waste. Participants (N = 113) completed questionnaires assessing intentions, attitude, perceived behavioural control, perceived norms, perceived importance, self‐identity, and past behaviour. Confirmatory factor analysis indicated that self‐identity and perceived importance were distinct constructs. Further, after accounting for TPB components and perceived importance, self‐identity explained a significant amount of additional variance in intentions. The present findings therefore do not support this particular argument against the predictive utility of self‐identity.     

Group processes in food choices: The role of ethnic identity and perceived ethnic norms upon intentions to purchase ethnical food products

A study tested an extended Theory of Planned Behaviour (TPB) model, inclusive of measures of ethnical identification and perceived ethnic group norms, in the ethnical food purchasing domain. One hundred and thirty‐five Jamaicans, living in the Brixton neighbourhood, London, were administered a self‐reported questionnaire measuring the classical TPB components (attitudes, subjective norms, perceived behavioural control, behavioural intentions) plus three additional components: identification with the Jamaican group, perceived norms of the Jamaican group and past behaviour. Results of hierarchical multiple regressions showed that past behaviour, ethnical identification and perceived group norms explain an additional proportion of variance in intentions, independently of attitudes, subjective norms and perceived control. A two‐way interaction, between ethnical identification and perceived group norms, was detected. A stronger relation between group norms and intentions emerged among high ethnical identifiers. Theoretical and practical implications are discussed. Copyright © 2008 John Wiley & Sons, Ltd.     

Predicting Psychologists' Intentions to Integrate Complementary and Alternative Therapies Into Their Practice

Drawing on an extended Theory of Planned Behaviour (TPB) framework, we employed a cross‐sectional design study to investigate psychologists' intentions to integrate complementary and alternative therapies (CAT) into their practice via recommending CAT to clients or referring clients to CAT practitioners. Participants were registered practicing psychologists from a range of therapeutic orientations (e.g., narrative, cognitive behavioural, psychodynamic). The psychologists were either recruited by phone, following a search of the Internet, or were contacted through their place of employment (hospitals, university counselling service). Those who agreed to participate (N = 122; n = 88 females, n = 34 males) completed a questionnaire that included standard TPB items of attitude, subjective norm, and perceived behavioural control, along with items measuring perceived risk, past behaviour, CAT knowledge, and gender. The outcome variables of interest were (a) intention to recommend CAT to clients and (b) intention to refer clients to CAT practitioners. Structural equation modelling revealed that the extended model was a good fit, explaining 69% (recommending CAT) and 51% (referring to CAT practitioners) of the variance in intentions. For both behaviours, direct paths from attitude and subjective norm to intentions were observed, with perceived risk and past behaviour influencing the TPB predictors of attitudes, subjective norm, and perceived behavioural control. The findings illustrate the role that cognitive and risk factors have on psychologists' decisions to integrate CAT into their practice. Understanding psychologists' cognitions and decisions about CAT integration forms an important basis on which to consider future changes in policy or practice.     

Testing an extended theory of planned behavior to predict young people's intentions to join a bone marrow donor registry

An extended theory of planned behavior (TPB) was used to understand the factors, particularly control perceptions and affective reactions, given conflicting findings in previous research, informing younger people's intentions to join a bone marrow registry. Participants (N = 174) completed attitude, subjective norm, perceived behavioral control (PBC), moral norm, anticipated regret, self‐identity, and intention items for registering. The extended TPB (except PBC) explained 67.2% of variance in intention. Further testing is needed as to the volitional nature of registering. Moral norm, anticipated regret, and self‐identity are likely intervention targets for increasing younger people's bone marrow registry participation.     

Students' online collaborative intention for group projects: Evidence from an extended version of the theory of planned behaviour

Given the increasing use of web technology for teaching and learning, this study developed and examined an extended version of the theory of planned behaviour (TPB) model, which explained students' intention to collaborate online for their group projects. Results indicated that past experience predicted the three antecedents of intention, while past behaviour was predictive of subjective norm and perceived behavioural control. Moreover, the three antecedents (attitude towards e‐collaboration, subjective norm and perceived behavioural control) were found to significantly predict e‐collaborative intention. This study explored the use of the “remember” type of awareness (i.e. past experience) and evaluated the value of the “know” type of awareness (i.e. past behaviour) in the TPB model.     

Predicting students’ intention to smoke by theory of planned behaviour variables and parental influences across school grade levels

Differences were examined in Theory of Planned Behaviour determinants of students’ intention to smoke including parents’ attitudes towards smoking and parents’ current cigarette use among Greek students of different school grade levels. Students (N?=?763) aged 10–18 years reported their attitudes towards smoking, subjective norms, perceived behavioural control, self-identity and intention to smoke while their parents (N?=?525) reported their attitudes towards smoking and their current cigarette use. All the TPB variables increased from lower to higher school grade level. Multi-sample path analyses showed that parent's attitudes towards smoking positively predicted students’ intention to smoke only for elementary school children. Parents’ current cigarette use did not contribute significantly. Students’ attitudes, perceived behavioural control and self-identity predicted systematically intention to smoke in contrast to the subjective norm that did not contribute at all. Perceived behavioural control contributed to a higher degree in intention to smoke for senior high school students compared to the junior high school and elementary students. Self-identity contributed to a higher degree in intention to smoke for elementary compared to the junior high school students. The results of this study suggests that the determinants of smoking vary between early and late adolescence.     

Sleep hygiene behaviours: An application of the theory of planned behaviour and the investigation of perceived autonomy support,past behaviour and response inhibition

This study investigated the sleep hygiene behaviour of university students within the framework of the Theory of Planned Behaviour (TPB [Ajzen, I. (1991). The theory of planned behavior. Organizational Behavior and Human Decision Processes, 50, 179–211.]), and examined the predictive validity of additional variables including perceived autonomy support, past behaviour and response inhibition. A total of 257 undergraduate students from an Australian university were administered two online questionnaires at two time points. At time 1, participants completed the TPB questionnaire and the Go/NoGo task as a measure of response inhibition. A week later at time 2, participants completed a questionnaire measuring the performance of sleep hygiene behaviours. Multiple and hierarchical regression analyses showed that the TPB model significantly predicted intention and behaviour. Although intention and perceived behavioural control were statistically significant in predicting behaviour, past behaviour and response inhibition accounted for more variance when added to the TPB model. Subjective norm was found to be the strongest predictor of intention implying the importance of normative influences in sleep hygiene behaviours. Response inhibition was the strongest predictor of behaviour, reinforcing the argument that the performance of health protective behaviours requires self-regulatory ability. Therefore, interventions should be targeted at enhancing self-regulatory capacity.     

Predicting People’s Intention to Donate Their Body to Medical Science and Research

Predictors of people’s intention to register with a body bequest program for donating their deceased body to medical science and research were examined using standard theory of planned behavior (TPB) predictors (attitude, subjective norm, perceived behavioral control) and adding moral norm, altruism, and knowledge. Australian students (N = 221) at a university with a recently established body bequest program completed measures of the TPB’s underlying beliefs (behavioral, normative, and control beliefs) and standard and extended TPB predictors, with a sub-sample reporting their registration-related behavior 2 months later. The standard TPB accounted for 43.6%, and the extended predictors an additional 15.1% of variance in intention. The significant predictors were attitude, subjective norm, and moral norm, partially supporting an extended TPB in understanding people’s body donation intentions. Further, important underlying beliefs can inform strategies to target prospective donors.     

Social identity and the transition to entrepreneurship: The role of group identification with workplace peers

What role does social identity play in the transition from employed work to entrepreneurship? It was expected that social identity affects the cognitive processes that, according to the theory of planned behavior (TPB), underlie the formation of entrepreneurial intentions. Focusing on academic scientists' intentions to commercialize research knowledge, we investigated social identity (scientists' group identification with their workplace peers in academia) as a moderator in the TPB model. Our hypotheses were tested in a sample of 488 German scientists. The data revealed that entrepreneurial intentions were predicted by attitude, social norms, and perceived control and that group identification was negatively associated with perceived control. Multi-group structural equation modeling further showed that group identification moderated the TPB-intention link. Scientists with low group identification based their entrepreneurial intentions not so much on social norms and attitudes but on their self-initiative and control beliefs. Among scientists with high group identification, in turn, entrepreneurial intentions were mainly a function of social norms. These results, in sum, illustrate the long-neglected importance of identification with, and social cohesion within, peer groups at the workplace for the transition to entrepreneurship.     

Predicting intention and behaviour following participation in a theory-based intervention to improve gluten free diet adherence in coeliac disease

Objective: To determine whether changes in theory of planned behaviour (TPB) constructs could predict intention and gluten-free diet (GFD) adherence following participation in an online theory-based intervention designed to improve adherence in coeliac disease.

Design: Theory-based process evaluation of the mechanisms of change over the course of a six-week online intervention. Measures of GFD adherence and TPB variables were administered at baseline and follow-up (immediate post-intervention: n = 74; three-month: n = 68; six-month: n = 65). Hierarchical regression analyses using residualised change scores were conducted at each time point (dependent variables: intention and adherence).

Results: Baseline intention and GFD adherence were the strongest predictors of follow-up intention and adherence, respectively. Change in attitude accounted for significant variance in intention. Change in intention accounted for significant variance in GFD adherence immediately post-intervention; by the six-month follow-up change in perceived behavioural control was the stronger predictor.

Conclusions: Partial support for the hypotheses suggests that, for certain behaviours, the TPB may be relevant in explaining the mechanism of action responsible for changes in intention and behaviour following participation in a behaviour change intervention. Additional predictive pathways are also likely to exist and, in the area of GFD adherence, may include habit strength and actual behavioural control.     

Analysing the Influence of Autonomous and Controlling Social Factors Within the Theory of Planned Behaviour

The aim of this study was to analyse the effects of autonomous (i.e., autonomy support from parents and peers) and controlling (i.e., social physique anxiety) social factors on future intention to exercise, integrating the distal (i.e., basic psychological needs satisfaction and self‐determined motivation) and proximal (i.e., attitudes, perceived behavioural control and subjective norms) determinants of intention defined in self‐determination theory (SDT) and the theory of planned behaviour (TPB). Self‐report questionnaires were distributed to 390 secondary school pupils (male = 218, female = 172, M_age = 15.10, standard deviation = 1.94). The results of path analysis, controlling for past behaviour of physical activity, showed that social factors predicted future intention to exercise through the influence of the distal and proximal determinants. The main contribution of the study was to provide evidence that the proximal determinants of the TPB captured the direct influence of social factors, independent of the mediating effects of psychological needs satisfaction and self‐determined motivation towards exercise. Results supported the integration of the two theories, clarifying the processes of influence of autonomous and controlling social factors within the variables of SDT and the TPB.     

Parental Control and Junk‐Food Consumption: A Mediating and Moderating Effect Analysis1

This cross‐sectional study examined the mediating effect of the theory of planned behavior (TPB) and the moderating role of perceived parental control within the context of adolescents' junk‐food consumption. Adolescents (N = 739) were selected using a cluster‐stratified randomized sampling method. Social cognitions, perceived parental control, and junk‐food consumption were assessed through self‐administered questionnaires. Results revealed both direct and indirect effect of perceived parental control within TPB. Additionally, impact of intention was not moderated by perceived parental control. TPB explained 28% and 12% of the variance in intention and junk‐food consumption, respectively. This study identified somewhat both the why and how of junk‐food consumption in Iranian female adolescents.     

Exploring the beliefs underpinning drivers’ intentions to comply with speed limits

Using the theory of planned behaviour (TPB; [Ajzen, I. (1985). From intentions to actions: A theory of planned behavior. In J. Kuhl, J. Beckmann (Eds.), Action control: From cognition to behavior (pp. 11–39). Berlin: Springer-Verlag.]) as a theoretical framework, the present study was designed to: (a) identify the beliefs underpinning drivers’ intentions to comply with speed limits, and (b) test the expectancy-value theory held to underpin those beliefs. A sample of drivers (N = 598) completed questionnaires designed to measure TPB variables with respect to compliance with speed limits. The results of hierarchical multiple regression analyses provided support for the expectancy-value theory held to underpin each behavioural beliefs (outcome beliefs X outcome evaluations), normative beliefs (referent beliefs X motivation to comply), and control beliefs (control frequency beliefs X control power beliefs). Belief targets for road safety countermeasures that aim persuade drivers to comply with speed limits were also identified by selecting those beliefs that were the statistically significant predictors of direct TPB measures (attitudes, subjective norm, perceived control) and intention. Theoretical and practical implications of the results are discussed.     

The Role of Self‐identity in the Theory of Planned Behavior: A Meta‐Analysis

The present study used meta‐analysis to evaluate the role of self‐identity in the theory of planned behavior (TPB). Altogether, 40 independent tests (N = 11607) could be included in the review. A large, sample‐weighted average correlation between self‐identity and behavioral intention was observed (r₊ = .47). Multiple regression analyses showed that self‐identity explained an increment of 6% of the variance in intention after controlling for the TPB components, and explained an increment of 9% of the variance when past behavior and the TPB components were controlled. The influence of self‐identity on behavior was largely mediated by the strength of behavioral intentions. Theoretical implications of the findings are discussed.     

Test of a brief theory of planned behaviour‐based intervention to promote adolescent safe sex intentions

The present study tested a brief (303 word) intervention designed to change attitude, subjective norm, and perceived behavioural control regarding a safe sex behaviour in a sample of 16‐ to 18‐year‐olds. Participants (N = 288) were randomized to receive either an experimental intervention or a control (knowledge only) intervention and completed measures of their reactions to the stimuli as well as pre‐ and post‐test measures of theory of planned behaviour variables. The experimental intervention significantly increased message processing (mean between‐group difference = 0.73, 95% CI = 0.40, 1.06; Cohen's d = .52), message acceptance (mean between‐group difference = 0.82, 95% CI = 0.57, 1.07; Cohen's d = .77), subjective norm (adjusted Mean between‐group difference = 0.54, 95% CI = 0.26, 0.81; Cohen's d = .37; mean within‐group difference for intervention condition = 0.59, 95% CI = 0.36, 0.81; Cohen's d = .38) and intention (adjusted Mean between‐group difference = 0.27, 95% CI = 0.02, 0.53; Cohen's d = .20; mean within‐group difference for intervention condition = 0.54, 95% CI = 0.33, 0.75; Cohen's d = .31), but not attitude or perceived behavioural control. The effects of the experimental intervention on intention were mediated solely through subjective norm. The present findings: (a) compare favourably in terms of the effect sizes reported in previous research in this area (mean Cohen's d for within‐group difference for intervention conditions = .009 and .09, for norms and intention, respectively, see Albarracín et al. (2003) ), (b) imply that subjective norms are causally related to intentions, and (c) suggest that interventions designed to change subjective norms (as opposed to communication of risks and fear appeals) might ultimately be effective in changing behaviour.