Since the inception of the theory of reasoned action in late 1970s by Martin Fishbein and Icek Ajzen, the theories of reasoned action and planned behavior and, in its more recent incarnation, the reasoned action approach, have been among the most influential approaches to predicting and understanding intentional behavior. The theories have been widely applied across multiple behaviors, contexts, and populations. With their roots in attitude theory and the social cognitive tradition, the theories focus on individuals’ beliefs with respect to future performance of a given behavior. The theory of reasoned action was the earliest version of the theory. The central construct of the theory is intention, a motivational construct that is considered the most proximal determinant of behavior. Intention reflects the extent to which an individual is likely to plan to do, and invest effort in pursuing, a given behavior. Intention is conceptualized as a function of two belief-based constructs: attitudes and subjective norms. Attitudes are positive or negative evaluations of performing the behavior in future, while subjective norms reflect beliefs that significant others would want them to perform the behavior. The theory of reasoned action demonstrated effectiveness in predicting variability in people’s behavior across many contexts, populations, and behaviors. Ajzen modified the theory of reasoned action to account for behaviors that were not under the complete control of the individual. The theory of planned behavior introduced perceived behavioral control as an additional predictor of intentions. In circumstances where individuals’ perceptions of control closely reflect actual control, perceived behavioral control would determine the strength of the Intention-Behavior Relationship. When their perceived behavioral control was high, individuals would be more likely to act on their intentions. Ajzen also proposed that when perceived behavioral control closely reflects actual control, it will directly predict behavior. Fishbein and Ajzen proposed the reasoned action approach as a further development in their theory based on research. The reasoned action approach extends the theory of planned behavior by differentiating between different subcomponents of the attitude, subjective norm, and perceived behavioral control constructs in the theory of planned behavior. The popularity of the theories is due to their relative simplicity and flexibility, as well as their effectiveness in accounting for substantive variance in behavior. The theories have also served as the basis for extended theories that encompass new constructs toward developing more comprehensive explanations of behavior, and to test salient processes that determine action such as the relationship between intentions and behavior. This annotated bibliography outlines key books, chapters, and articles that chart the progress of these theories from their origins and development to their application and extension. The list of readings offered in this bibliography is not exhaustive, but aims to provide readers with a representative overview of the origins of the theories, key theoretical assumptions and debates, the empirical evidence testing the theories, and research on extensions and practical application of the theories.

We present a meta-analytic review of studies measuring implicit and explicit attitudes in child and adolescent samples. A meta-analytic structural equation model revealed that both implicit and explicit attitudes independently predicted behavior, with a larger effect size for explicit attitudes. Moderator analyses revealed larger effects of implicit measures on behavior for social bias behaviors compared to diet and health-related behaviors and aggression behaviors. Age did not moderate the size and relative contribution of both forms of attitude on behavior, and the implicit-explicit attitude correlation. Studies adopting a fixed order of attitude measure presentation, rather than counterbalanced, and those using the implicit association test to measure implicit attitudes exhibited stronger implicit attitude-behavior effects than those adopting other measures. Findings support an additive model for the effects of implicit and explicit attitudes on behavior in children and adolescents, and provide formative evidence to guide future research using implicit measures in younger populations.

Illustration of a basic model of a behavior change mechanism. The diagram illustrates the process by which the content of a behavioral intervention (often a behavior change method or technique) affects change in a behavioral outcome through change in a construct representing the psychological process from behavioral theory.

Objective: Implicit attitudes toward behaviors develop over time through repeated experience of behaviors alongside associated evaluations. Implicit attitudes can be activated on presentation of cues or other behaviorally-relevant information, which may also activate an associated behavioral response. The implicit attitude-behavior link means that the associated behavioral response is likely to be non-consciously and automatically enacted. Implicit attitude strength should, therefore, moderate effects of behavioral automaticity on subsequent behavior. Methods: The moderating effect of implicit attitudes on effects of automaticity on health behavior was investigated using a two-wave correlational design. Two samples of University students completed measures of attitudes, behavioral automaticity, and implicit attitudes for free-sugar intake (sample 1) and heavy episodic drinking (sample 2) at an initial time point, with follow-up behavioral measures taken at two and five weeks later, respectively. Results: Moderated path analyses indicated that attitudes and behavioral automaticity predicted behavior in both samples. Implicit attitudes moderated the automaticity-behavior relationship in both samples. The effect of behavioral automaticity on behavior was largest when implicit attitudes were high. Conclusions: Findings provide important preliminary evidence that individuals with strong implicit attitudes are more likely to enact their behavior automatically rather than as part of an intentional process.

Objective: There is continued debate regarding the most useful and meaningful way to measure habit and how to form habits via intervention. To date, lay representations of habit have rarely been explored. Such understandings may provide clarity on how researchers might better define habit, develop valid measurements of habit, and evaluate habit-based interventions. This study aimed to explore how lay people represent habit, across two studies. Methods: Study 1 (N = 158) used an online, open-ended questionnaire to elicit what lay people believe to be the salient features of habit. Study 2 involved a series of interviews and focus groups (N = 27), to explore individual representations of habit. Results: Theoretical thematic content analysis across the two studies revealed that participants described habit by what it is (i.e., an explicit outcome or internal mechanism), by habit’s features (i.e., automatic, frequent, stable cue/context, and emotionally rewarding), and by how they evaluated habits (i.e., being both “good” and “bad”). When describing the characteristics of habitual behaviours, participants identified that habits were either simple, discrete behaviours; clustered, repetitive behaviours synonymous with routine; or a self-identity characteristic. Conclusions: Current findings indicate that lay people hold consistent and contradictory representations of habit. Largely, lay representations were similar to scientific conceptualisations, with some notable difference. Participants appeared to misunderstand the cue-based mechanism of habits, interchangeably used ‘habit’ with ‘routine’, and believed that habits were emotionally rewarding. Future research should focus on integrating the beliefs identified in this research with new measures of habit and habit interventions.