by Marina Koren
The English language is rife with idioms that cast thoughts as physical objects, as if they are actual possessions of the mind: She holds a strong opinion. That argument carries little weight. They gave you the wrong idea.
Now, researchers have found that treating thoughts like tangible material goes beyond figures of speech, reports a recent study in Psychological Science. When participants wrote down negative thoughts about body image or a type of diet on a piece of paper and threw it away, they were less affected by them when later evaluating their attitudes on these topics; their initial blues didn’t translate into a negative outlook. On the other hand, those who jotted down positive thoughts and tucked the note into their pockets for safekeeping were more likely to be influenced by them—their ratings reflected a positive skew.
The science involves what's called embodied cognition: the well-established idea that the body and its movements can shape thought.
In one experiment, a group of high school students from Spain wrote down either positive or negative thoughts about their body images and then reflected on the notes. One group was instructed to throw them in the trash, while another was told to read over them to check for grammar mistakes. Those in the “write it out, toss it out” condition were less affected by the negative thoughts later, when they were asked to rate their bodies.
“The movements kind of invalidated their thoughts,” says study co-author Richard Petty, a psychology professor at Ohio State University. In the act of physically disposing of something, "they're mentally saying, ‘Oh, these thoughts are no good.’”
In another experiment, Spanish students were asked to list either positive or negative thoughts on a piece of paper about the Mediterranean diet, a fairly innocuous topic, Petty says. One group physically threw their written thoughts away, another kept them in a pocket, and a control group folded the corners of the page. All then rated their feelings about the diet, indicating whether they’d make the switch to the olive oil-loving lifestyle.
Participants who generated and threw out negative thoughts reported more favorable evaluations of the diet than those who were asked to generate positive thoughts. Treating those thoughts as trash meant participants didn’t use them to bash the diet. On the flip side, keeping positive thoughts close magnified their impact, and participants who did so rated the diet more favorably. Protecting these thoughts made them more salient, suggests Petty.
A third experiment found that participants could reduce the influence of negative thoughts without putting pen to paper: the effect held even when they composed thoughts on a computer and deleted them digitally. But simply visualizing dragging an electronic file full of negative or positive thoughts about the diet to either the recycle bin or a storage disk on a computer wasn’t enough—to actually change their thought process, participants needed to use a mouse to move the document.
“Imagination doesn’t have the same impact,” Petty says. “You need to really do it. We can’t fool ourselves and pretend. It's similar to when you want to get rid of a real object, but it's still in the room and you try to pretend it’s not there.”
While envisioning trashing a bad thought won't do the trick, writing or typing is not a requirement. Even subtle movements like nodding or shaking your head can help you mentally discard—or keep—thoughts, according to a 2003 study Petty published in the Journal of Personality and Social Psychology. Participants were more persuaded by an argument when nodding along to it rather than when shaking their heads.
“It doesn’t really matter what the thoughts are about,” Petty says. “Positive thoughts make you less positive if you throw them away or shake your head no, but if you’re nodding your head up and down and keeping them close to you, positive thoughts become more impactful.”
The lesson? Don't be ashamed to preserve a happy message from a fortune cookie in your wallet— but deposit that hate mail right in the trash.
Marina Koren is an editorial intern at Psychology Today.