Chapter 6 Theory of Reasoned Action Theory of

Chapter 6: Theory of Reasoned Action, Theory of Planned Behavior, and the Integrated Behavior Model

Overview Ø Origins & Historical Developments Ø Theory of Reasoned Action (TRA) Ø Theory of Planned Behavior (TPB) Ø Integrated Behavior Model (IBM) Ø Application of Theories Ø Summary

Origins and Historical Developments

Overview • The TRA and TPB have constructs concerned with individual motivational factors as determinants of performing specific behaviors • Underlying assumption: – Intention is best predictor of behavior

Historical Development • TRA was developed to understand relationships between attitudes, intentions, and behaviors (Fishbein, 1967) • Previous attitude theorists focused on attitude toward an object; – Fishbein demonstrated attitude toward the behavior is a better predictor of that behavior • Principle of compatibility

Historical Developments • TRA was developed by Fishbein in 1969 from attitude measurement theory – Attitude is determined by expectations/beliefs concerning attributes of the object or action and evaluation of those attributes • Expectancy-value conceptualization • TBP was developed in 1985 by Ajzen et al. to improve upon the predictive power of the TRA – Addresses the lack of volitional control in the TRA

Historical Developments • The IBM was developed in the early 2000 s – Based on the work of several individuals and organizations that called for the consideration of the similarities and differences in health behavior theories – Sought to identify a critical set of variables that serve as the key determinants of behavior

Theory of Reasoned Action (TRA)

Theory of Reasoned Action The most important determinant of behavior is behavioral intention • Direct determinants of behavioral intentions: – Attitudes toward performing behavior • Determined by beliefs about outcomes/attributes of performing the behavior – Subjective norms associated with a behavior • Determined by normative beliefs —whether referent individuals approve/disapprove of performing the behavior

Theory of Reasoned Action

Theory of Reasoned Action • TRA best explains/predicts behavior for which individuals exercise a large degree of control – May be insufficient to predict behaviors in which volitional control is reduced

Theory of Planned Behavior (TPB)

Theory of Planned Behavior • Perceived behavioral control was added to the TRA to form the TPB (Ajzen, 1991) – Accounts for factors outside individual control that may affect intentions and behaviors – Determined by: • Control beliefs —concerning the presence or absence of facilitators and barriers to behavioral performance • Perceived power—impact of each control factor to facilitate or inhibit behavior

Theory of Planned Behavior: An Extension of Theory of Reasoned Action

Theory of Reasoned Action and Theory of Planned Behavior

TRA and TPB • Major strengths: – Hypothesized causal relationships among model components are clearly specified – Measurement and computation of constructs specified • Demographic and environmental characteristics assumed to operate through model constructs – Not thought to independently contribute to behaviors

Measurement of Constructs • Measures – Behavioral beliefs: bipolar “unlikely-likely” or “disagree-agree” scales (-3 to +3) – Evaluation of outcomes: bipolar “good-bad” scales (-3 to +3) – Normative beliefs: Bipolar scale (-3 to +3) – Motivation to comply: Unipolar “agree-disagree” scale (1 -7) – Control beliefs: Bipolar “unlikely-likely” (-3 to +3) – Perceived power: Bipolar “easy-difficult” scale

Measurements of Constructs • Can calculate indirect measures for: – Subjective norm – Perceived behavioral control • Can calculate direct measures of each model component – Should be strongly associated with: • Intentions and behaviors • Indirect measures

Testing TRA and TPB • Prospective study designs preferred to crosssectional designs to establish time order • Determine relative weights of model constructs empirically for each behavior and population – Behaviors can be under attitudinal, normative, or perceived control • Varies by behavior and population

Integrated Behavioral Model (IBM)

Integrated Behavioral Model • Includes constructs from TRA, TPB, and other influential theories • Most important determinant of behavior is motivation or intention to perform behavior

Integrated Behavioral Model

Integrated Behavioral Model • Components affecting behavior 1. 2. 3. 4. 5. 6. Motivation Socio-cultural factors Knowledge and skill to carry out behavior Environmental constraints Salience Habits or past performance • Behavior most likely to occur if the above conditions are met

Integrated Behavioral Model • Behavior intention determined by: 1. Attitude toward the behavior 2. Perceived normal or social influence 3. Personal agency To design an effective intervention influencing behavioral intentions, it is necessary to first determine the degree to which all three influence intention

Integrated Behavioral Model • Other demographic, personality, and individual variables may be associated with behavior – Influence hypothesized to be indirect, operating via theoretical constructs

Application of Theories (TRA, TPB, and IBM)

Elicitation Phase: TRA, TPB, IBM • Intentions can be influenced by variety of behavioral, normative, efficacy, and control beliefs – Vary by behavior and population • Critical to conduct open-ended elicitation interviews with target population to identify relevant behavioral outcomes, referents, and contributing factors for each behavior and population

Elicitation Phase: TRA, TPB, IBM

Steps to IBM Application 1. Specify behavior – In terms of action, target, context, and time 2. Conduct qualitative interviews for elicitation phase 1. Design a culturally appropriate instrument to measure constructs – Include pilot testing

Steps to IBM Application 4. Determine which constructs best explain intention and should be focus for intervention 4. Analyze and identify specific beliefs that are best targets for communication interventions 4. Design communication messages and materials 4. Evaluate effectiveness of messages

Summary

Summary • Individual level health behavioral theories • TRA, TPB, and IBM provide structure to understand how various beliefs affect behavioral intention – TRA: behaviors under volitional control – TPB: behaviors that are under less volitional control – IBM: incorporates TRA and TPB constructs in addition to others