Skip to Main Content

Prejudices Are Bad for Everybody, Study Finds

Biases Reduce Physical, Mental, Social Well-Being

Khanh Dinh studies how our prejudices negatively affect our mental, social and physical well-being.

06/17/2011
By Sandra Seitz

Prejudice is bad for its victims. Many studies have shown how discrimination harms a person or group – in quality of life, job opportunities and more.

Khanh Dinh has a different question.

“To really address the problems of discrimination, we must ask, ‘How does it affect us, who harbor prejudicial attitudes?’ ” says Dinh, associate professor in the Psychology Department. “Do we gain or suffer from being prejudiced?”

Looking for Answers

The topic is an important one to explore, according to Dinh.

“I think of prejudice as social pollution,” she says. “Just as we breathe polluted air, we absorb biased attitudes and society suffers. We need to learn how to identify this pollution and reduce it.”

Hypothesizing that prejudicial attitudes would have negative health effects, Dinh led an investigation to find out. The research team, which included graduate student Michelle Holmberg and Asst. Profs. Ivy Ho and Michelle Haynes, all of the Psychology Department, studied whether increased levels of prejudice are associated with poorer measures of mental, social and physical health.

The team surveyed 500 undergraduate students, from all across the campus, using measures of bias toward race, gender, sexual orientation, physical disability, body size or immigrant status. The study was conducted in spring 2010 and the surveys were anonymous. 

Surprising Results Show a Syndrome

“We were surprised to find that prejudicial attitudes tended to generalize,” says Dinh. “We had thought that a person might show bias in a particular area because of prior experience, but not in others.” 

A student could have grown up in a racially charged atmosphere with resulting bias, for example, without being homophobic or biased toward the physically disabled. But, the level of bias tended to be consistent across all categories. 

Dinh says, “There may be a prejudicial syndrome, linking diverse forms of prejudice that share a common, underlying cause.”

Prejudice Affects Well-Being

The researchers also measured five indicators of personal well-being: level of depression, social support network, presence of physical symptoms, general perceived health status and self-esteem. 

Using statistical analysis, they controlled for the demographic factors of age, gender and socio-economic status.

“We also controlled for level of self-esteem, thinking that a low self-esteem, in itself, could account for negative attitudes toward others,” says Dinh.

The results? 

“Prejudice has a powerful and harmful effect,” says Dinh. “The higher one’s level of prejudice, the more likely one is to have poorer measures of mental, social and physical well-being. The two strongest in their effect are racial prejudice and sexism.”

“These correlations raise an interesting question,” says Dinh. “Perhaps an intervention that successfully reduced one sort of prejudice would generalize to others. 

Another Surprise

One prejudice didn’t fit the pattern. People with bias against obesity showed less depression and better physical health.

“This may have a cultural basis,” says Dinh. “Being thin in our society has lots of positive reinforcement, while negative attitudes toward the obese continue to be culturally acceptable.”

The study, with its provocative findings, will be presented at the annual convention of the American Psychological Association in August.