➡️ Video Lesson: Intro to the Theory of Planned Behavior
➡️ Study Card
➡️ Introduction
The theory of planned behavior is a model that predicts human behavior based on three factors: personal attitudes, subjective norms, and perceived behavioral control.
The three key factors are explained below:
- Personal attitudes – If we want to predict a person’s future behaviors, we need to look at their personal attitudes. For example, if a person has a positive attitude toward exercising, then they’re more likely to go to the gym.
- Subjective norms – If we want to predict a person’s future behavior, we need to look at the social and cultural norms they adhere to. For example, if someone’s culture glorifies and celebrates soccer, then the person may be more likely to play soccer.
- Perceived behavioral control – If we want to predict a person’s future behavior, we need to look at how much they believe they can control their own behavior and whether they can achieve change through effort (see also: locus of control theory).
Ajzen (1991), the founder of the theory, provides a concise definition below:
“Attitudes toward the behavior, subjective norms with respect to the behavior, and perceived control over the behavior are usually found to predict behavioral intentions with a high degree of accuracy”
(Ajzen, 1991, p.206)
Theory of Planned Behavior Examples
1. Volunteering at a Local Shelter
Type: Personal Attitudes
Mark starts volunteering at a local animal shelter because he feels a strong sense of compassion for animals. He believes that his efforts can make a positive difference in the lives of abandoned pets. This personal attitude motivates him to dedicate his free time to the shelter every weekend.
2. Recycling at Home
Type: Subjective Norms
Sarah begins recycling at home because all her neighbors and friends are doing it. She notices that her community places a high value on environmental responsibility, and she feels social pressure to conform to this norm. Seeing others recycle encourages her to follow suit.
3. Choosing a Vegetarian Diet
Type: Subjective Norms
Tom decides to adopt a vegetarian diet after many of his friends and colleagues make the switch for ethical reasons. The social environment around him promotes the idea that avoiding meat is the right thing to do, influencing his dietary choices based on the behavior of those he respects and admires.
4. Attending the Gym Regularly
Type: Perceived Behavioral Control
Emily starts attending the gym regularly because she feels confident in her ability to fit it into her schedule and manage her workouts. She has easy access to a gym near her home and believes she can maintain this routine despite her busy lifestyle. This sense of control over the behavior makes her commitment more sustainable.
5. Saving Money for a Vacation
Type: Perceived Behavioral Control
John begins saving money for a vacation because he believes he has the financial discipline and budgeting skills to do so. He feels confident that by cutting unnecessary expenses, he can accumulate the funds needed for his trip. His perceived control over his spending habits drives his saving behavior.
6. Reducing Plastic Usage
Type: Personal Attitudes
Lisa starts reducing her plastic usage because she feels strongly about protecting the environment. She has read about the harmful effects of plastic pollution and wants to contribute to a cleaner planet. Her personal belief in the importance of environmental conservation motivates her to change her habits.
7. Joining a Yoga Class
Type: Subjective Norms
Kevin joins a yoga class because many of his colleagues and friends are practicing yoga and speaking highly of its benefits. He feels a social expectation to participate and experiences a desire to fit in with his social group. The positive views of those around him influence his decision to start yoga.
8. Switching to a Plant-Based Diet
Type: Personal Attitudes
Jason decides to switch to a plant-based diet after watching several documentaries about the benefits of eating more fruits and vegetables and the negative impacts of meat consumption on health and the environment. He develops a strong belief that a plant-based diet will improve his health, reduce his carbon footprint, and help prevent animal suffering. This shift in his personal attitudes towards food and health drives his commitment to adopting and maintaining this dietary change.
9. Participating in Workplace Diversity Initiatives
Type: Personal Attitudes
Rachel becomes actively involved in her company’s diversity and inclusion initiatives because she firmly believes in the importance of a diverse and inclusive work environment. She has always valued fairness and equality and feels that participating in these initiatives aligns with her personal values and attitudes. Her strong belief in social justice motivates her to take on a leadership role in organizing and promoting diversity events and workshops at her workplace.
10. Composting Organic Waste
Type: Personal Attitudes
Carlos starts composting his kitchen waste because he is passionate about sustainable living and reducing his environmental footprint. He has read extensively about the benefits of composting and how it can help reduce landfill waste and improve soil health. His positive attitude towards sustainability and waste reduction drives his commitment to this new practice, even though it requires extra effort and a change in his daily routines.
11. Joining a Running Club
Type: Subjective Norms
Amy decides to join a running club because many of her friends and colleagues are members and often talk about their experiences and achievements. She notices that running is a popular and socially valued activity in her social circle, and she feels a sense of pressure to participate and be part of the group. Seeing her friends’ enthusiasm and hearing their success stories influence her decision to start running and join the club, hoping to gain social acceptance and improve her fitness.
12. Participating in Local Elections
Type: Subjective Norms
Ben becomes more engaged in local elections after noticing that his family, friends, and community members place a high importance on civic participation. Discussions about local issues and candidates are common in his social circles, and he feels a sense of obligation to be informed and involved. The strong social norm around civic duty and participation influences his decision to vote in every election and even volunteer for local campaigns.
13. Reducing Sugar Intake
Type: Subjective Norms
Emma decides to reduce her sugar intake after noticing that many of her colleagues and friends are making similar changes to their diets. Conversations about health and wellness are frequent, and reducing sugar is often highlighted as an important step. Feeling the social pressure to conform to these healthier habits, Emma starts paying more attention to her sugar consumption and opts for healthier alternatives, influenced by the health-conscious norms of her social group.
14. Learning to Cook
Type: Perceived Behavioral Control
Nathan starts learning to cook because he feels confident in his ability to follow recipes and manage his time in the kitchen. He has access to numerous cooking tutorials and resources, which makes him believe that he can acquire the necessary skills. His sense of control over the learning process and his ability to practice regularly motivate him to start cooking more meals at home, gradually improving his culinary skills.
15. Adopting a Daily Reading Habit
Type: Perceived Behavioral Control
Michael decides to adopt a daily reading habit because he feels confident that he can carve out time each day to read. He has a collection of books he is eager to explore and believes that setting aside just 30 minutes a day for reading is manageable. This sense of control over his schedule and his ability to maintain this new habit drives his commitment to becoming a more consistent reader.
➡️ Strengths and Weaknesses of the Theory
Theory of Planned Behavior Strengths and Weaknesses
| Strengths | Weaknesses |
|---|---|
| The theory has a wider diversity of contributing factors than other theories of motivation, such as the locus of control theory, which only focuses on one of the three factors examined in the theory of planned behavior. | The theory may not necessarily accurately predict behavior all of the time. This is particularly true if unexpected events or factors occur during a scenario that cannot fit into the three categories in the theory. |
| The theory has a substantive number of empirical studies backing it, reflecting its usability, applicability, and ability to stand up to rigorous testing. | The theory fails to look at subconscious factors that may affect decision making. It tends instead to focus on conscious decision-making processes. This focus on the conscious mind may not fully capture the complexity of human behavior. |
| The theory’s use of subjective norms helps it to take into account cultural factors, making it applicable across various social and cultural contexts. | The theory doesn’t spell out a spectrum of motivations, unlike other motivation theories such as the self-determination theory. |
Conclusion
The theory of planned behavior has been applied to explain a wide range of human behavior, from likelihood of exercising to engaging in environmentally friendly behavior such as recycling.
Although many studies have demonstrated the explanatory value of the model, no model is perfect. Human behavior is complex, multidimensional, and not always a result of reasoned action.
Therefore, this model has never been able to explain the actions under study with 100% accuracy.
To be fair, it is highly unlikely that a model that reaches such a degree of accuracy will ever be devised. In the meantime, this theory has proven to be quite useful and will improve as additional key factors are identified and incorporated.
➡️ References and Further Reading
References
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, Heidelber, New York: Springer-Verlag.
Ajzen, I. (1991). Theory of planned behavior. Organizational Behavior and Human Decision Processes, 50(2), 179–211.https://doi.org/0.1016/0749-5978(91)90020-T
Bosnjak, Michael & Ajzen, Icek & Schmidt, Peter. (2020). Theory of Planned Behavior: Selected Recent Advances and Applications. Europe’s Journal of Psychology, 16, 352-356. https://doi.org/10.5964/ejop.v16i3.3107
Godin, Gaston & Kok, Gerjo. (1996). Theory of Planned Behavior: A Review of Its Applications to Health-Related Behaviors. American Journal of Health Promotion, 11, 87-98. https://doi.org/10.4278/0890-1171-11.2.87
Reger, B., Cooper, L., Booth-Butterfield, S., Smith, H., Bauman, A., Wootan, M., et al. (2002). Wheeling walks: A community campaign using paid media to encourage walking among sedentary older adults. Preventive Medicine, 35, 285–292.
Hardeman, W., Johnston, M., Johnston, D. W., Bonetti, D., Wareham, N. J., & Kinmonth, A. L. (2002). Application of theory of planned behaviour change interventions: A systematic review. Psychology and Health, 17, 123-158.
Masud, M.M.; Al-Amin, A.Q.; Junsheng, H.; Ahmed, F.; Yahaya, S.R.; Akhtar, R.; Banna, H. (2016). Climate change issue and theory of planned behaviour: Relationship by empirical evidence. Journal of Cleaner Production, 113, 613–623.
Zobeidi, T., Yaghoubi, J. & Yazdanpanah, M. (2022). Exploring the motivational roots of farmers’ adaptation to climate change‑induced water stress through incentives or norms. Science Reports, 12, 15208. https://doi.org/10.1038/s41598-022-19384-1
Dr. Cornell has worked in education for more than 20 years. His work has involved designing teacher certification for Trinity College in London and in-service training for state governments in the United States. He has trained kindergarten teachers in 8 countries and helped businessmen and women open baby centers and kindergartens in 3 countries.
This article was peer-reviewed and edited by Chris Drew (PhD). The review process on Helpful Professor involves having a PhD level expert fact check, edit, and contribute to articles. Reviewers ensure all content reflects expert academic consensus and is backed up with reference to academic studies. Dr. Drew has published over 20 academic articles in scholarly journals. He is the former editor of the Journal of Learning Development in Higher Education and holds a PhD in Education from ACU.