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December 7, 2006

Beliefs Impact Behavior

Public Health Practitioners Can Change Health Decisions, but Can’t Explain Why an Intervention Works for Some but Not Others

The study of health behavior is really a way to determine how to design interventions that change or reinforce beliefs, explained Martin Fishbein, PhD, the Harry C. Coles, Jr. Distinguished Professor in Communication at the Annenberg School of Communication at the University of Pennsylvania. However, “it’s not that we can’t change beliefs, it’s that we can’t tell you why the intervention was successful in changing those beliefs.”

Fishbein spoke at the one-year anniversary of the Johns Hopkins Bloomberg School of Public Health’s Department of Health, Behavior and Society. The “birthday party,” as Department Chair David Holtgrave, PhD, affectionately referred to the gathering, was held on World AIDS Day.

Co-creater with Izek Ajzen of the Theory of Reasoned Action, Fishbein explained that his theory suggests that people’s decision to perform a particular behavior is determined by their individual attitude toward performing the behavior. It also takes into account the subjective norm people hold of what their significant others think they should or should not do.

In general, an individual will hold a favorable attitude toward a given behavior if they believe that performing the behavior will lead to mostly positive outcomes. The same applies for negative attitudes and behaviors; a person is less likely to perform a behavior if they believe the behavior will have a negative outcome.

According to Fishbein, the most effective behavior interventions are directed at changing specific behaviors, not behavioral categories. As an example—losing weight—an intervention to jog for twenty-minutes twice a week will work better than an intervention that targets the concept of exercising.

Fishbein explained that his theory and other behavior prediction theories help public health practitioners identify the beliefs that need to be addressed in order to reinforce or change any given behavior. However, theories do not tell practitioners how to reinforce or change beliefs.

Quoting Maya Angelou, Holtgrave said, “When we know better, we do better.” Relating back to the department’s anniversary and its mission to impact health behavior, Holtgrave noted that faculty research from the School’s newest department has looked into a variety of topics, including the availability of car seats for obese children, the HIV viral load of homeless individuals, and the positive impact of South African soap operas on HIV awareness.

“I salute the faculty, staff and students of Health Behavior and Society on their accomplishments in our first year and their faith in signing up for a journey into uncharted waters,” said Holtgrave. “It is often said that there is nothing so practical as a good theory and no one has proven this more than Professor Fishbein. We will use theories such as his to inform the construction of our interventions.”

Public Affairs media contacts for the Johns Hopkins Bloomberg School of Public Health: Kenna Lowe or Tim Parsons at 410-955-6878 or