This is apparently true: People who buy or even see pictures of organic, healthful food are more likely to be ungenerous, judgmental and self-interested than people who buy or see pictures of standard or unhealthful foods.
Rachel Herz, who studies the psychology of neuroscience, included that tidbit in her book "Why You Eat What You Eat." The book, which is scientific in nature but written in language any layperson can understand, is crammed full of similar information.
"But to the extent that I have received hate mail about this book, it has been about that," Herz said in a recent interview from her home office in Rhode Island.
Of course, it is the people who buy organic food who write the hate mail, she said, which kind of proves her point. She went on to cite studies showing that people who go to Whole Foods-the Mecca of self-righteous shopping-tend to behave badly in the parking lot.
Buying organic foods feels like they are doing a good deed, and "you feel like you are morally licensed to be a jerk because you have done your good deed for the day," she said.
The first part of "Why You Eat What You Eat" is about how our senses affect our eating in surprising ways, and the second part shows the unexpected ways that social and psychological factors have an impact on our relationship to food.
For instance, people who drink bloody marys report that they taste better on an airplane than on the ground. According to a study cited by Herz, they are right-and it is because of our sense of hearing.
Loud noises have been shown to make salty foods taste less salty, sweet foods less sweet and sour foods less sour. Noise apparently has no effect on the taste receptors that sense bitter foods.
But loud noises actually enhance the taste of umami, which is the flavor of earthiness found in mushrooms, meat-and tomatoes. So the sound inside an airplane does indeed make tomato juice taste better.
Then there is the problem with the color red. Red foods lead our brains to think that what we eat is going to be good, or at least sweet. For example, people think red grapes are sweeter than green, when they actually have the same amount of sweetness. That makes sense, Herz said, because our evolutionary ancestors learned that red fruit was riper and sweeter than green.
On the other hand, red can also act as a kind of warning not to eat something, and this, too, is in our evolutionary hard-wiring.
A German university asked more than 100 visitors to fill out some questionnaires. Next to one group, they put out a red paper plate containing 10 pretzels. Next to another, it was a blue plate, and a white plate was given to a third group. The people with the red plate ate only half as many pretzels as those with the blue or white plates.
Why? According to Herz, it is because our ancestors learned to associate red as a sign of warning. Blood is red, as is inflammation and also poison berries.
So while the color red can indicate a desirable level of sweetness, it also, "at the very least, draws our attention. It makes us think and be on alert. I think being on alert is a good cautionary state to be in," Herz said.
Her previous books were about the sense of smell, which is her specialty, and what it means to be disgusted by something. The reaction of disgust is related to our sense of taste, she said; we have the same response to something vile as to something that tastes bitter because our evolutionary ancestors learned to associate a bitter taste with something noxious and potentially deadly.
Herz wrote this third book because of her fascination with food and eating, she said. Eating "should be an immensely pleasurable act," she said. The more you know about it, the better it should be.
"It's the idea that with the information that this book imparts, you, the reader, ought to be in control of your relationship with food, rather than have food be in control of you," she said.