Quick quiz: Two women, Jen and Sue, both age 34, are considering their lunch options. This morning, Jen had a wholesome, hearty breakfast and washed down a multivitamin with fresh orange juice. Sue, on the other hand, picked up a double latte and muffin at Starbucks. Who is more likely to order the organic salad for lunch, and who is more likely to stuff themselves at the all-you-can eat buffet?
A new study says it's Jen who will be piling her plate with potato salad and brownie bites. Researchers at National Sun Yat-Sen University in Taiwan have found that taking a multi-vitamin makes people feel invulnerable to the health consequences of other choices. It's as if that pill magically transforms us into a "healthy person," or erases the effects of our indulgences. This means that if you a pop a pill with your OJ, you're less likely to ponder the risks of not just what you eat, but other decisions: Get the flu shot, or skip it this year? Exercise, or watch tv? Put on the sunscreen, or go for a tan?
In the new study, the researchers randomly assigned adults to take either a pill labeled "multi vitamin" or a pill that was openly acknowledged to be a placebo (both were actually placebos). Then they tracked participants' preferences and behaviors across two health domains -- eating and exercising. Participants who thought they had taken a vitamin were less likely to pursue the healthier choice: They were more likely to choose an indulgent buffet over a healthy, organic meal, and they were less interested in, and spent less time, exercising.
What's going on? To this health psychologist, it's a clear case of "licensing." Licensing refers to a common trick of the mind first identified by Princeton psychologists studying prejudice and discrimination. When we do one thing that earns us "credits" (e.g. rejecting an obviously sexist or racist statement to earn "moral credentials," or taking a multivitamin to earn health points), we feel liberated to pursue the opposite goal. So a human resources officer who recently hired a minority or a woman may feel licensed to ignore concerns about diversity or fairness in the next hiring decision, and - as we see in this new study - people who take a vitamin feel licensed to skip the gym and hit the buffet line.
This study is not just a good example of licensing; it might also explain the confusing and contradictory evidence about whether taking vitamins improves health or reduces risk. There's no consensus because the data is all over the place; some studies say it helps, others say it doesn't -- and may even increase risk. Maybe that's because even in a randomly controlled study, we can't control how one new health behavior will shift participants' thinking and decisions. Sometimes doing one new healthy thing can motivate additional healthy choices; other times, it may pave the way for self-sabotage.
I've written about licensing before; in my experience, it is one of the most common traps people fall into when trying to make a behavior change. They take one step forward and feel so good about themselves (I bought the store-brand laundry detergent! I'm a super saver!) that they reward themselves by switching goals (I deserve a little splurge - I can afford to go out for dinner.)
Licensing is a mysterious process; people sometimes license themselves when they simply imagine doing a virtuous deed. For example, people who imagine exercising are more likely to reward themselves with a candy bar, and people who imagine volunteering some of their time to a charity feel less guilty about hitting the mall for retail therapy.
But licensing can also be avoided when we remind ourselves of why we did that "good deed" in the first place. When you're making that second choice, if you can remember that your biggest goal is health (or being fair and unbiased, or saving money, etc.), the licensing effect seems to disappear.
So if you want to take a vitamin, go ahead -- but when you take it, instead of focusing on how it's making you healthier, remind yourself of your desire to make healthy choices.
Study Cited:
1. Wen-Bin Chiou, Chao-Chin Yang and Chin-Sheng Wan. Ironic Effects of Dietary Supplementation: Illusory Invulnerability Created by Taking Dietary Supplements Licenses Health-risk Behaviors. Psychological Science, (in press)
