Integrating the theory of planned behaviour and self‐determination theory in health behaviour: A meta‐analysis

Purpose A meta‐analysis of studies integrating the theory of planned behaviour (TPB) and self‐determination theory (SDT) in health contexts is presented. The analysis aimed to provide cumulative empirical support for a motivational sequence in which self‐determined motivation from SDT predicts the proximal predictors of intentions and behaviour from the TPB. Methods A literature search identified 36 integrated studies providing 45 tests of effects between TPB and SDT variables. Hunter and Schmidt's (1994) methods of meta‐analysis were used to correct the effect sizes across the studies for statistical artifacts. Age (old versus young), publication status (published versus unpublished), study design (correlational versus experimental/intervention), and behaviour type (physical activity versus other health‐related behaviours) were evaluated as moderators of the effects. A path‐analysis using the meta‐analytically derived correlations was conducted to examine the proposed motivational sequence. Results Statistically significant corrected correlations were evident among the perceived autonomy support and self‐determined motivation constructs from SDT and the attitude, subjective norms, perceived behavioural control, intention, and health‐related behaviour constructs from the TPB. Only six of the 28 effect sizes were moderated by the proposed moderators. Path analysis revealed that the significant effects of self‐determined motivation on intentions and behaviour were partially mediated by the proximal predictors from the TPB. Conclusions Evidence from this synthesis supported the theoretical integration and proposed motivational sequence. Results are discussed with reference to the complementary aspects of the TPB and SDT and the need for integrated experimental or intervention studies on a broader range of health behaviours.     

Theory of planned behaviour cognitions do not predict self‐reported or objective physical activity levels or change in the ProActive trial

Objective. The objective was to test, in a trial cohort of sedentary adults at risk of Type 2 diabetes, whether theory of planned behaviour (TPB) cognitions about becoming more physically active predicted objective and self‐reported activity levels and change. Design. Participants of a randomized controlled trial underwent measurement at baseline, 6 and 12 months. Methods. Participants (N= 365, 30–50 years) were recruited via their parent or family history registers at 20 general practices in the UK. Energy expenditure was measured objectively at baseline and 1 year. Participants completed questionnaires assessing physical activity and beliefs about becoming more physically active over the next year at baseline, 6 and 12 months. Results. Between baseline and 12 months, objective energy expenditure in the cohort increased by an average of 20 minutes of brisk walking per day. Based on the 252 participants who provided complete data, affective attitude and perceived behavioural control consistently predicted intention, but intention and perceived behavioural control failed to predict physical activity levels or change (p‐values > .05). Conclusions. Failure of the theory to predict behaviour and behaviour change may be due to inapplicability of the theory to this at‐risk population or to trial participation and intensive measurement facilitating behaviour change without affecting measured cognitions, or lack of correspondence between cognitive and behavioural measures. A wide range of potential personal and environmental mediators should be considered when designing physical activity interventions among at‐risk groups. High‐quality experimental tests of the theory are needed in clinical populations.     

Testing an integrated model of the theory of planned behaviour and self‐determination theory for different energy balance‐related behaviours and intervention intensities

Objectives The aim of the study was to test the relations between constructs from the self‐determination theory (autonomous and controlled motivation), the theory of planned behaviour (attitudes, self‐efficacy, and intentions), and behaviour change within a theoretically integrated model. Additionally, the aim was to test if these relations vary by behaviour (physical activity or dietary behaviour) or intervention intensity (frequency). Design. It was a randomized controlled trial with a ‘usual care’ condition (medical screening only) and an intervention condition (medical screening+access to a website and coaching). Participants in the latter condition could freely determine their own intervention intensity. Methods. Participants (N= 287) completed measures of the theoretical constructs and behaviour at baseline and after the first intervention year (N= 236). Partial least squares path modelling was used. Results. Changes in autonomous motivation positively predicted changes in self‐efficacy and intentions towards a healthy diet. Changes in controlled motivation positively predicted changes in attitudes towards physical activity, changes in self‐efficacy, and changes in behavioural intentions. The intervention intensity moderated the effect of self‐efficacy on intentions towards physical activity and the relationship between attitude and physical activity. Changes in physical activity were positively predicted by changes in intentions whereas desired changes in fat intake were negatively predicted by the intervention intensity. Conclusions Important relations within the theoretically integrated model were confirmed but others were not. Moderation effects were found for behaviour and intervention intensity.     

Blunted cardiovascular responses to acute psychological stress predict low behavioral but not self‐reported perseverance

Emerging evidence relates attenuated physiological stress reactions to poor behavioral regulation. However, only a small number of behaviors such as impulsivity and risk taking have been explored. Nevertheless, one opportunistic study suggested that blunted reactivity might relate to poor perseverance. The present study examined the relationship between cardiovascular reactivity to acute active psychological stress and self‐reported and behavioral perseverance. Participants (N = 64) completed a self‐report perseverance questionnaire before heart rate (HR) and blood pressure (BP) were measured at rest and in response to 4‐min active (paced auditory serial addition; PASAT) and passive (cold pressor) stress tests. This was followed by an unsolvable Euler puzzle tracing task, with the time spent and number of attempts endeavoring to solve the puzzle recorded as behavioral perseverance measures. Blunted systolic and diastolic BP reactivity to the PASAT was associated with fewer attempts at the impossible puzzle, and lower diastolic BP PASAT reactivity related to less time persevering at the puzzle. Moreover, attenuated diastolic BP and HR PASAT reactivity predicted poorer perseverance at keeping one's hand in the iced water of the cold pressor task. There was no association between reactivity and self‐reported perseverance. These preliminary findings add to the evidence that implicates blunted reactivity as a physiological marker of poor behavioral regulation, and this may indicate why individuals with blunted reactivity are at increased risk of developing negative health outcomes (e.g., obesity and addictions).     

Help‐seeking intentions for breast‐cancer symptoms: A comparison of the self‐regulation model and the theory of planned behaviour

Purpose: Delays in seeking help for symptoms have been found to be associated with poorer outcome in breast‐cancer patients. This study explores symptom perceptions and health beliefs as predictors of intentions to seek medical help in a general female population. The utility of the self‐regulation model of illness cognition and the theory of planned behaviour were examined in predicting help‐seeking intentions for potential symptoms of breast cancer in a general population sample. Methods: A general population sample of 546 women completed a postal questionnaire comprising items examining components of the self‐regulation model and the theory of planned behaviour. Help‐seeking intention was determined by asking participants to rate the likelihood of visiting their GP for a range of breast symptoms. Results: Hierarchical multiple regression analysis revealed that the cognitive component of the self‐regulation model accounted for approximately 22% of the variance in help‐seeking intention. Identity (β = 0.45, p < .001) emerged as a significant predictor of intention to seek help. Inclusion of the components of the theory of planned behaviour accounted for an additional 7% of the variance; the significant predictors were attitude to help‐seeking (β = 0.19, p <.001) and perceived behavioural control (β = 0.12, p <.01). Conclusions: Intention to seek medical help for a potential breast‐cancer symptom may be mediated, partly, by cognitive representations of the identity and consequences of breast cancer and by attitudes towards help‐seeking and perceived behavioural control. Although less than one‐third of the variance was accounted for, these results have important implications for future research (in terms of identifying which variables should be examined) and for the development of a model of help‐seeking behaviour in women with breast‐cancer symptoms.     

The theory of planned behaviour and binge drinking: Assessing the moderating role of past behaviour within the theory of planned behaviour

A sample of 398 undergraduate students completed questionnaires assessing the main constructs of the theory of planned behaviour (TPB) in relation to binge drinking, as well as past binge drinking behaviour. Of these, 273 were followed up at 1 week. Regression analyses revealed attitude, self‐efficacy, and perceived control (negative relationship) to be predictive of binge drinking intentions. Intention and self‐efficacy were, in turn, predictive of binge drinking at 1‐week follow‐up. Past behaviour was found to explain additional variance in intention and behaviour. In addition, past behaviour was found to moderate the attitude–intention and intention–behaviour relationships, such that weaker relationships were observed with increasing frequency of past behaviour. The results are discussed in relation to the need to develop and test alternative measures of habit. The implications of the findings for interventions to encourage more appropriate drinking behaviour are outlined.     

The Rescorla-Wagner theory does not predict contextual control of phasic responses in transswitching

Theoretical predictions regarding differential phasic responding to the same phasic conditioned stimulus in two different tonic contexts, generated by a computer simulation of the Rescorla-Wagner theory of classical conditioning, were compared to empirical evidence of phasic switching in two studies of transswitching of the skin conductance response in humans. Significant phasic switching was found in both studies, but the Rescorla-Wagner theory substantially underestimated the obtained differences. It was shown that the theory predicts phasic differences that are more in accord with empirical data when the salience (alpha) of the contextual stimuli is assumed to be much greater than the salience (alpha) of the phasic conditioned stimulus. This modification in salience relationships, however, makes the Rescorla-Wagner theory more like Asratyan's theory of transswitching. Analysis of both tonic and phasic differentiation in experimental groups run with two different phasic stimuli AND two different tonic stimuli or with two phasic stimuli and only one tonic stimulus provided support for the conclusion that tonic response differentiation is a necessary precondition for obtaining phasic switching. It is suggested that the Rescorla-Wagner theory fails to account for phasic switching because it treats tonic and phasic stimuli as essentially equivalent, ignoring the fact that the tonic stimulus is present prior to the time that phasic stimuli occur and that responses to the tonic stimuli can occur during the period following tonic stimulus onset and preceding the administration of phasic stimuli.     

Towards a theory of intentional behaviour change: Plans,planning, and self‐regulation

Purpose Briefly review the current state of theorizing about volitional behaviour change and identification of challenges and possible solutions for future theory development. Method Review of the literature and theoretical analysis. Results Reasoned action theories have made limited contributions to the science of behaviour change as they do not propose means of changing cognitions or account for existing effective behaviour change techniques. Changing beliefs does not guarantee behaviour change. The implementation intentions (IMPs) approach to planning has advanced theorizing but the applications to health behaviours often divert substantially from the IMPs paradigm with regard to interventions, effects, mediators and moderators. Better construct definitions and differentiations are needed to make further progress in integrating theory and understanding behaviour change. Conclusions Further progress in theorizing can be achieved by (a) disentangling planning constructs to study their independent and joint effects on behaviour, (b) progressing research on moderators and mediators of planning effects outside the laboratory and (c) integrating planning processes within learning theory and self‐regulation theory.     

Blunted cardiovascular reactivity to acute psychological stress predicts low behavioral but not self‐reported perseverance: A replication study

Emerging evidence suggests that individuals with poor behavioral perseverance show low or blunted physiological responses to acute psychological stress. For example, a recent preliminary laboratory study demonstrated that blunted responders give up sooner and take fewer attempts when endeavoring to complete an impossible puzzle, but do not self‐report poor perseverance. This present research is a replication of the previous study with an increased sample size, longer recovery periods between tasks and addition of social evaluation to the cold pressor. Participants (147) completed a self‐report perseverance questionnaire (Short Grit Scale) and behavioral perseverance tasks (impossible Euler puzzle and socially evaluated cold‐pressor (SECPT)). The number of attempts and time spent trying to complete the unsolvable puzzle, and duration of hand submergent during the SECPT, were recorded as behavioral perseverance measures. Difference in blood pressure (BP) and pulse rate (PR) from baseline to a 10‐min paced auditory serial addition task (PASAT) were computed as reactivity. As previously, reactivity did not relate to self‐reported perseverance and blunted BP reactivity to the PASAT was associated with less time persevering at the unsolvable puzzle. Additionally, blunted BP and PR reactivity to the PASAT related to poorer perseverance during the SECPT. These findings, replicating the previous study, increase confidence that blunted reactivity is a physiological marker of poor behavioral perseverance. Moreover, given that self‐reported perseverance does not relate to reactivity, this suggests that blunted responders are not conscious of this detriment in perseverance, but likely need additional support when persistence is critical (e.g., during behavior change).     

The expectancy‐value muddle in the theory of planned behaviour — and some proposed solutions

The authors of the Theories of Reasoned Action and Planned Behaviour recommended a method for statistically analysing the relationships between beliefs and the Attitude, Subjective Norm, and Perceived Behavioural Control constructs. This method has been used in the overwhelming majority of studies using these theories. However, there is a growing awareness that this method yields statistically uninterpretable results (Evans, 1991). Despite this, the use of this method is continuing, as is uninformed interpretation of this problematic research literature. This is probably due to the lack of a simple account of where the problem lies, and the large number of alternatives available. This paper therefore summarizes the problem as simply as possible, gives consideration to the conclusions that can be validly drawn from studies that contain this problem, and critically reviews the many alternatives that have been proposed to address this problem. Different techniques are identified as being suitable, according to the purpose of the specific research project.     

Comparing solutions to the expectancy‐value muddle in the theory of planned behaviour

Objectives The authors of the Theories of Reasoned Action (TRA) and Planned Behaviour (TPB) recommended a method for statistically analysing the relationship between the indirect belief‐based measures and the direct measures of attitude, subjective norm, and perceived behavioural control (PBC). However, there is a growing awareness that this yields statistically uninterpretable results. This study's objective was to compare two solutions to what has been called the ‘expectancy‐value muddle’. These solutions were (i) optimal scoring of modal beliefs and (ii) individual beliefs without multiplicative composites. Design Cross‐sectional data were collected by telephone interview. Methods Participants were 110 first‐degree relatives (FDRs) of patients diagnosed with colorectal cancer (CRC), who were offered CRC screening in the study hospital (83% response rate). Participants were asked to rate the TPB constructs in relation to attending for CRC screening. Results There was no significant difference in the correlation between behavioural beliefs and attitude for rescaled modal and individual beliefs. This was also the case for control beliefs and PBC. By contrast, there was a large correlation between rescaled modal normative beliefs and subjective norm, whereas individual normative beliefs did not correlate with subjective norm. Conclusions Using individual beliefs without multiplicative composites allows for a fairly unproblematic interpretation of the relationship between the indirect and direct TPB constructs ( French & Hankins, 2003 ). Therefore, it is recommended that future studies consider using individual measures of behavioural and control beliefs without multiplicative composites and examine a different way of measuring individual normative beliefs without multiplicative composites to that used in this study.     

Loading during the stance phase of walking in humans increases the extensor EMG amplitude but does not change the duration of the step cycle

 Prior work from mammals suggests that load experienced by extensor muscles of the hindlimbs (i.e. Duysens and Pearson 1980; Pearson and Collins 1993; Fouad and Pearson 1997) or cutaneous afferents from the plantar surface of the foot (Duysens and Pearson 1976; Guertin et al. 1995) enhances activity in extensor muscles during the stance phase, and delays the onset of flexor activity associated with the swing phase. The presumed functional significance of this phenomenon is that extensor activity of the supporting limb during walking can: (a) reinforce the supporting function in proportion to the load experienced, and (b) prolong the stance phase until unloading of the limb has occurred. Whether a similar functional role exists for load-sensitive afferents during walking in the human is unknown. In this study, the effect of adding or removing a substantial load (30% of body weight) at the centre of mass was studied in healthy adult human subjects. Loads were applied near the centre of mass to avoid the need for postural adjustments which might confound the interpretation of the results. Subjects walked on a treadmill with either: (a) a sustained increase or decrease in load, or (b) a sudden unexpected increase or decrease in load. In general, subjects responded to the changes in load by changing the amplitude of the extensor electromyographic (EMG) bursts. For example, with sudden unexpected additions in load, the average increase in amplitude was 40% for the soleus across the stance phase, and 134% for the quadriceps during the early part of the stance phase. Extensor EMGs increased with both sustained and sudden increases in load. Extensor EMG durations also increased (average increase in duration of 4% for soleus with sudden loading, and 7% for sustained loading). Cycle duration hardly changed (average increase of 0.5% with both sudden and sustained loading). These results differ from those of infants subjected to a similar perturbation during supported walking. A large change in timing (i.e. an increase in the duration of the stance phase by 30% and the step cycle by 28%) was seen in the infants, with no change in the amplitude of the EMG burst (Yang et al. 1998). These results suggest that the central nervous system can control the timing and amplitude of extensor EMG activity in response to loading independently. Maturation of the two components most likely occurs independently. In the adult, independent control of the two components may provide greater flexibility of the response. Received: 28 April 1998 / Accepted: 3 September 1998     

Objective but not subjective sleep predicts memory in community‐dwelling older adults

Research on the relationship between habitual sleep patterns and memory performance in older adults is limited. No previous study has used objective and subjective memory measures in a large, older‐aged sample to examine the association between sleep and various domains of memory. The aim of this study was to examine the association between objective and subjective measures of sleep with memory performance in older adults, controlling for the effects of potential confounds. One‐hundred and seventy‐three community‐dwelling older adults aged 65–89 years in Victoria, Australia completed the study. Objective sleep quality and length were ascertained using the Actiwatch 2 Mini‐Mitter, while subjective sleep was measured using the Pittsburgh Sleep Quality Index. Memory was indexed by tests of retrospective memory (Hopkins Verbal Learning Test – Revised), working memory (n‐back, 2‐back accuracy) and prospective memory (a habitual button pressing task). Compared with normative data, overall performance on retrospective memory function was within the average range. Hierarchical regression was used to determine whether objective or subjective measures of sleep predicted memory performances after controlling for demographics, health and mood. After controlling for confounds, actigraphic sleep indices (greater wake after sleep onset, longer sleep‐onset latency and longer total sleep time) predicted poorer retrospective (?R² = 0.05, P = 0.016) and working memory (?R² = 0.05, P = 0.047). In contrast, subjective sleep indices did not significantly predict memory performances. In community‐based older adults, objectively‐measured, habitual sleep indices predict poorer memory performances. It will be important to follow the sample longitudinally to determine trajectories of change over time.     

Prospect theory does not describe the feedback‐related negativity value function

Humans handle uncertainty poorly. Prospect theory accounts for this with a value function in which possible losses are overweighted compared to possible gains, and the marginal utility of rewards decreases with size. fMRI studies have explored the neural basis of this value function. A separate body of research claims that prediction errors are calculated by midbrain dopamine neurons. We investigated whether the prospect theoretic effects shown in behavioral and fMRI studies were present in midbrain prediction error coding by using the feedback‐related negativity, an ERP component believed to reflect midbrain prediction errors. Participants’ stated satisfaction with outcomes followed prospect theory but their feedback‐related negativity did not, instead showing no effect of marginal utility and greater sensitivity to potential gains than losses.     

Testing an extended theory of planned behaviour to predict young people's sun safety in a high risk area

Objectives The present research examined the sun protection intentions and behaviours of young people in a high risk skin cancer area using an extended theory of planned behaviour (TPB) incorporating additional social influences of group and image norms. Design The study employed a prospective design to examine young people's sun protection intentions and behaviour. Method Participants (N = 1,134), aged 12–20 years, were students (school, university, TAFE) and young employees living in Queensland, Australia. Participants completed a questionnaire assessing the TPB predictors (attitude, subjective norm, perceived behavioural control) and additional social influences (group norm, image norm) of sun protection intentions. Two weeks later, participants (N = 734) reported their sun protection behaviour for the previous fortnight. Results Results revealed that the TPB variables of attitude, subjective norm and perceived behavioural control and the additional social influence variable of group norms, but not image norms, emerged as significant predictors of intentions to engage in sun protection. The extended TPB variables accounted for 36% of the variance in intentions. For behaviour, the extended TPB variables accounted for 27% of the variance with both intention and, unexpectedly, group norm as the significant direct predictors of sun protective behaviours. Conclusions Results of this study provide support for the application of the TPB in the sun safety context and highlight the importance of considering the influence of group norms in the development of future interventions to increase young people's sun protection intentions and behaviour.