There’s nothing in particular that qualifies someone with several years of TV, film, or commercial acting experience to tell us what’s good for our bodies. But there’s a difference between listening to a celebrity blab on about some expensive age-defying moisturizer and listening to one that tells you not to vaccinate your kids.
So why do we drink the Kool Aid? Two researchers from Canada’s McMaster University and the Harvard School of Public Health came up with a list of possible reasons. According to Steven Hoffman and Charlie Tan, a number of theories drawn from economics, marketing, psychology, and sociology could explain why the average viewer might buy into Jenny McCarthy’s anti-vaccine nonsense, or Katie Couric’s misguided HPV vaccine alarmism. Published in the British Medical Journal‘s Christmas issue, they are as follows:
“When celebrities endorse a product or idea, they differentiate it from others,” the authors write. The idea of signals, taken from the field of economics, means that celebrities’ strident and well-publicized tones distinguish themselves from the noise. We could be more likely to listen to them just because they appear more boldly than the conflicting or nuanced views of family or friends
Celebrities are trendsetters, and often we follow their lead. As an example, the researchers cite Angelina Jolie’s double mastectomy after learning she had tested positive for the BRCA1 gene mutation. Jolie’s decision led to a heightened interest in genetic testing, researchers say, though testing is usually only suggested for women with a high risk or family histories of breast cancer.
Sometimes we confuse “nice hair,” “charisma,” and “good teeth” for other virtues we seek to emulate. Hoffman and Tan discuss the history of tobacco marketing in Hollywood films: If a celebrity dragging on a cigarette is considered cool or masculine, the public then associates coolness or masculinity with cigarettes.
It turns out that people who act for a living are often very good at it. Displaying a sense of authenticity in connection to a product or medical advice, whether that connection is authentic or not, can be very believable, especially in the glow of celebrity wealth, popularity, and power. “This credibility may stem from the halo effect of celebrities’ success, which biases people’s judgments of celebrities’ other traits and gives them a cloak of generalized trustworthiness that extends well beyond their industry or expertise,” the researchers write.
Similar to the halo effect, the notion of classical conditioning in psychology refers to training subjects to receive two stimuli with similar responses. (Think Pavlov’s dog drooling at the ringing of a bell.) When celebrities give medical advice, we might associate that advice with positive perceptions of the celebrity, whether or not it’s valid.
If we see celebrities as versions of our ideal selves, their hawked products and snake oil magic also become part of that ideal self. “Inspirational” celebrities in particular might encourage viewers to buy into whatever they’re saying, and the viewers might do so out of a desire to elevate their own self-esteem.
Cognitive dissonance is the uncomfortable conflict between two sets of values. Because we like to maintain consistency and avoid discomfort, reducing cognitive dissonance might mean we trivialize or ignore the conflict. Think, for example, of supporting R. Kelly by buying his music, but also shrugging off his history of sexual assault allegations. We might unconsciously support medical quackery from celebrities as long as it doesn’t interfere with our adulation or enjoyment of those celebrities.
“The widespread uptake of celebrity medical advice can also be explained as a social contagion that diffuses through social networks, which are systems of people linked through personal connections,” the researchers write. If everyone is linked to Kevin Bacon by six degrees, his opinions might exert some small amount of influence, but his newsworthiness and star power exert much more.
Just like some cultures believed eating the parts of an enemy might allow the eater to gain the foe’s power, our culture believes that consuming celebrity products allows us to embody some of that celebrity. “People ‘purchase’ celebrity by acquiring celebrities’ products, mimicking their lifestyles, and heeding their medical advice,” the study says. “These parasocial relationships have been conceptualised as a means of acquiring celebrities’ social capital: the benefits and resources accrued through social relationships.” Meaning, if we buy into celebrities’ terrible medical advice, we feel we’re raising our own social status, in a sense.
Of course, not all celebrities give bad advice. Jamie Oliver, for instance, uses his status as a celebrity chef to promote healthy eating in elementary schools. Creative public health campaigns can also use marketing lessons to their advantage, and find ways to make a signal in the noise. Take, for example, this terrifying (but also extremely clickable) interactive on the effects of smoking on the human body.