1. Theory of Reasoned Action and Theory of Planned Behavior
CHAPTER 5
Theory of Reasoned Action and Theory of Planned Behavior

2. Historical Evolution
1960s: Theory of reasoned action (TRA) was introduced by Martin Fishbein to explain the relationship between attitudes and behavior
1970s: Fishbein teamed up with Icek Ajzen of the University of Massachusetts, Amherst, to write the book Belief, Attitude, Intention and Behavior: An Introduction to Theory and Research
1980s: TRA was extensively studied with health behaviors and interventions
1990s: An extension of TRA, the theory of planned behavior (TPB), is introduced
2009: Death of Fishbein

3. Assumptions of TRA
Assumes that people are rational and that reasoning is the primary determinant of behavioral intent
Distinguishes between an attitude toward an object and an attitude toward behavior, for example, the object of breast cancer versus the behavior of seeking mammography
Does not take into account the elements of fear or irrational thought

4. Principles of TRA
Includes measures of attitudes and social normative perceptions that determine behavior
Addresses relationships among beliefs (behavioral and normative), attitudes, intentions, and behavior
Attitudes toward a particular behavior and beliefs about subjective norms can be highly predictive of behavior (30%–40%)

5. TRA and TPB
Figure 5-1: The upper portion including proximal constructs of attitude toward behavior and subjective norm constitute the theory of reasoned action; all three proximal constructs together constitute the theory of planned behavior.

6. TRA Construct 1: Behavior
Usually this is a single action performed by an individual that is observable
Examples are condom use, eating five servings of vegetables and fruits, and so on

7. TRA Construct 1 (cont’d)
Sometimes behavioral categories involve a set of actions that are not easily observable rather than a single observable action
Examples are being physically active every day, eating healthy, and so on
Behavior should be defined in terms of its target, action, context, and time (TACT)

8. TRA Construct 2: Behavioral Intention
Perceived likelihood of performing the behavior
Intention is a proximal measure of behavior
Measured on a bipolar scale of extremely improbable (–3) to extremely probable (+3)
Among the most important determinants of behavior
For example, a person who intends on exercising in the next week is likely to exercise

9. TRA Construct 3: Attitude Toward Behavior
Two components
Behavioral beliefs: Beliefs that behavioral performance is associated with certain attributes or outcomes
Evaluation of behavioral outcomes (outcome evaluation): Values associated with a behavioral outcome or attribute

10. TRA Construct 4: Behavioral Belief
Belief that behavioral performance is associated with certain attributes or outcomes
Measured on a unipolar scale of extremely unlikely (1) to extremely likely (7)
For example, a person who believes that exercise is likely to tone muscles is likely to exercise

11. Computing Behavioral Beliefs
Exercising daily will result in toning of muscles for me (Behavioral belief…1)
Extremely Extremely
Unlikely Likely
(Collect data for all possible beliefs on the subscale)

12. TRA Construct 5: Outcome Evaluations
Value attached to a behavioral outcome or attribute
Measured on a bipolar scale of bad (–3) to good (+3)
Interacts with behavioral belief
For example, a person who believes that exercise is likely to tone muscles but does not care about how toned his or her muscles are is unlikely to exercise

13. Computing Outcome Evaluations
Toning muscles is (Attitudinal Evaluation ...1)
Bad – – – Good
(Collect data for all possible evaluations on the subscale)

14. Computing Attitude Score Toward a Behavior
Multiply each behavioral belief by the evaluation ratings for each outcome evaluation and then sum all of the products; the result is the score for attitude toward behavior

15. TRA Construct 6: Subjective Norm
Subjective norm refers to one’s belief that most of the significant others in one’s life think one should or should not perform the behavior
For example, a person may think that if he or she exercises, his or her spouse would be proud of that person

16. TRA Construct 6 (cont’d)
Two components
Normative beliefs: Beliefs about whether each referent approves or disapproves of the behavior
Motivation to comply: Motivation to adhere to what each referent thinks the person should do

17. TRA Construct 7: Normative Belief
Belief about whether each referent approves or disapproves of the behavior
Measured on a bipolar scale of disagree (–3) to agree (+3)
For example, if a person believes that his or her family members approve of his or her waking up early in the morning and jogging, he or she is likely to jog

18. Computing Normative Beliefs
List salient referents from elicitation interviews for the behavior.
My family approves of my early-morning jogging:
Disagree – – Agree
(Collect data for all possible beliefs on the subscale)

19. TRA Construct 8: Motivation to Comply
Motivation to adhere to what each referent thinks the person should do
Measured on a unipolar scale of unlikely (1) to likely (7)
For example, if a person believes that his or her family members want him or her to jog early in the morning, he or she is likely to jog

20. Computing Motivation to Comply
How likely is it that my family wants me to jog early in the morning?
Unlikely Likely
(Collect data for all possible motivations on the subscale)

21. Computing Subjective Norm Score
Multiply normative belief by motivation to comply for each referent and then sum across all referents; the result is the score for the construct of subjective norm

22. Added Construct TPB 9: Perceived Behavioral Control
How much a person feels he or she is in command of enacting the given behavior
Two components
Control beliefs: Perceived likelihood of occurrence of facilitating or constraining conditions
Perceived power: Perceived effect of conditions in making behavioral performance difficult or easy

23. TPB Construct 10: Control Belief
Beliefs about internal and external factors that may inhibit or facilitate the performance of the behavior
Measured on a unipolar scale of unlikely (1) to likely (7)
For example, the likelihood of jogging when it is raining outside

24. Computing Control Beliefs
How likely is it that I will jog when it is raining outside?
Very Unlikely Likely
(Collect data for all possible beliefs on the subscale)

25. TPB Construct 11: Perceived Power
Perception about how easy or difficult it is for performing the behavior in each condition identified in control beliefs
Measured on a scale of difficult (–3) to easy (+3)
For example, when it is raining, it is very difficult to jog

26. Computing Perceived Power
How difficult is it to jog when it is raining outside?
Very Difficult –3 –2 – Very Easy
(Collect data for all possible conditions on the subscale)

27. Computing Perceived Behavioral Control Score
Multiply control beliefs by perceived power for each referent, and then sum across all control factors; the result is the score for the construct of perceived behavioral control

28. Application of TPB
Figure 5-2: How the theory of planned behavior can be used for promoting condom use behavior.

29. Strengths of TRA and TPB
© Gustavo Frazao/Shutterstock
Precise guidance regarding measurement
Help interventions to focus on the most important factors
Evaluation of TRA and TPB components at baseline and after the intervention help discern changes over time

30. Limitations of TRA and TPB
Are not behavior change theories but explain relationships among beliefs, intentions, and behaviors
Do not consider personality-related factors, cultural factors, and demographic variables that also shape behavior
Provide precise definitions for measurement of constructs (one of the best) but little guidance for modification
Focus only on rational thoughts and do not consider irrational thoughts or fears

31. Limitations of TRA and TPB (cont’d)
Measurement is time consuming and cumbersome (relies on interviewer administering personal interview)
Intervention messages may change one belief in the desired direction while adversely affecting another belief
© Aquir/Shutterstock

32. Application Exercise
One TPB example is the study by O’Neill and colleagues (2008) that examined behavioral intentions for adherence to mammography.
Besides the constructs of TPB, they included previous barriers, previous mammography maintenance, and age as potential predictors.

33. Application Exercise (cont’d)
A cross-sectional survey design was used and administered to 2,062 currently adherent women who were due for their mammograms in 3 to 4 months.
All TPB variables significantly predicted (p<0.05) behavioral intention except for subjective norms.
Locate the full-text article of this study and in a critique of 250 words comment on how TPB has been used in this study.

34. Application Exercise (cont’d)
In your critique pay attention to
How the constructs were reified
Were they operationalized adequately?
Was validity and reliability of the instrument established?
Were the statistical analyses appropriate?
Were the conclusions accurate?
Can the results be generalized?

35. Websites to Explore Applying TPB for Obesity Prevention
Constructing Questionnaires on TRA & TPB
You Tube: TPB

36. Websites to Explore (cont’d)
Professor Icek Aizen (Ajzen)
Resource Center For Adolescent Pregnancy Prevention (RECAPP)
University of Twente: TPB & TRA

37. Skill Building Activity
Choose a health behavior.
Diagrammatically draw how you would apply TRA to modify that behavior.
Neatly word process your diagram using software of your choice.
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