BIO
Icek Ajzen (Chelm, Poland) obtained his PhD in Social Psychology from the University of Illinois Urbana-Champaign (United States) in 1969. Two years later he was appointed Professor of Social Psychology at the University of Massachusetts Amherst, where he has spent most of his research career, alternating his work there with a series of visiting and other positions at Tel Aviv University. Currently Professor Emeritus at UMass Amherst, he has also headed its Division of Personality and Social Psychology on three separate occasions (1980-85, 1997-99 and 2001-12). Considered the researcher with the highest impact publications in the social psychology field (more than 530,000 citations), his most influential books are Attitudes, Personality, and Behavior (2005); Prediction and Change of Health Behavior: Applying the Reasoned Action Approach (2007), with Dolores Albarracín and Robert Hornik; and Predicting and Changing Behavior: The Reasoned Action Approach, with Martin Fishbein (2010).
CONTRIBUTION
Izek Ajzen is the father of one of the most impactful models in the field of social psychology for explaining, predicting and modifying human behavior: the Theory of Planned Behaviour (TPB). The professor first proposed this model in 1985 in a chapter of the book Action-control: From cognition to behavior and and later developed it in a seminal 1991 paper published in Organizational Behavior and Human Decision Processes.
The TPB, developed with the late Martin Fishbein, postulates that a person’s behavior is based on their intention, which rests in turn on three fundamental factors: their attitude towards the behavior in question (positive or negative evaluation towards performing the action); subjective norms (perceived social pressure to act in a given way, based on beliefs about the expectations of family members, friends and society in general); and perceived control of the behavior or self-sufficiency (that is, the individual’s perception of the ease or difficulty of performing the action, according to the resources, abilities and opportunities at their command).
Ajzen notes that the weight of these three factors depends on the behavior you’re dealing with and the context: “It has been found that in advanced societies like the United States the chance of a person getting vaccinated against a pandemic like COVID 19 will depend essentially on their personal attitude to that behavior, based on whether they think it is worth getting the jab. In African countries, conversely, what counts most is the difficulty. It’s more a question of control, of getting access to the vaccine.”
In the past forty years, his model has been applied in over 2,000 research projects. These applications run from public health (the promotion of vaccination, the use of condoms to prevent AIDS or the practice of physical activity) to the environment (for example, how to encourage use of public transportation over private vehicles). The usefulness of the model is also currently being investigated in the field of technology use, specifically with regard to the transfer of private data by individuals to online apps.
