Bothered by negative, unwanted thoughts? Just throw them away

On the other hand, people were more likely to use their thoughts when making judgments if they first wrote them down on a piece of paper and tucked the paper in a pocket to protect it.

"However you tag your thoughts -- as trash or as worthy of protection -- seems to make a difference in how you use those thoughts," said Richard Petty, co-author of the study and professor of psychology at Ohio State University.

Some types of psychological therapy use variations of this concept by trying to get patients to discard their negative thoughts. But Petty said this is the first study he is aware of that has validated that approach.

"At some level, it can sound silly. But we found that it really works -- by physically throwing away or protecting your thoughts, you influence how you end up using those thoughts. Merely imagining engaging in these actions has no effect."

The findings suggest that people can treat their thoughts as material, concrete objects, Petty said. That is evident in the language we use.

"We talk about our thoughts as if we can visualize them. We hold our thoughts. We take stances on issues, we lean this way or that way. This all makes our thoughts more real to us."

Petty conducted the research with Pablo Briñol, Margarita Gascó and Javier Horcajo, all of the Universidad Autónoma de Madrid in Spain.

The results are published online in the journal Psychological Science and will appear in a future print edition.

For the study, the researchers conducted three related experiments.

In the first experiment, 83 Spanish high school students participated in a study they were told was about body image. Each participant was told to write down either positive or negative thoughts about his or her body during a three-minute period.

All the participants were asked to look back at the thoughts they wrote. Researchers told half of the students to contemplate their thoughts and then throw them in the trash can located in the room, "because their thoughts did not have to remain with them." The other half were told to contemplate their thoughts and check for any grammar or spelling mistakes.

The participants then rated their attitudes about their own bodies on three 9-point scales (bad-good, unattractive-attractive, like-dislike).

Results showed that for those who kept their thoughts and checked them for mistakes, it mattered whether they generated positive or negative thoughts about their bodies. As would be expected, participants who wrote positive thoughts had more positive attitudes toward their bodies a few minutes later than did those who wrote negative thoughts.

However, those who threw their thoughts away showed no difference in how they rated their bodies, regardless of whether they wrote positive or negative thoughts.

"When they threw their thoughts away, they didn't consider them anymore, whether they were positive or negative," Petty said.

In a second study, 284 students participated in a similar experiment, except this time they were asked to write negative or positive thoughts about something most people believe is good: the Mediterranean diet (the diet emphasizes high consumption of fruits, vegetables, legumes and unrefined cereals, with olive oil as the basic fat).

In this case, some threw the thoughts away, some left them on their desk, and some were told to put the paper in their pocket, wallet or purse and keep it with them.

All participants were then asked to rate their attitudes toward the diet and intentions to use the diet for themselves.

As in the first study, those who kept the list of thoughts at their desk were more influenced by them when evaluating the diet than were those who threw them away. However, those who protected their thoughts by putting them in a pocket or purse were even more influenced than those who kept the thoughts on their desk.

In other words, those who wrote positive thoughts about the Mediterranean diet and put those thoughts in their pocket rated the diet more favorably than those who wrote positive thoughts and simply kept those thoughts on their desk. And, those who wrote negative thoughts and put them in their pocket rated the diet more negatively than those who kept their thoughts on the desk.

"This suggests you can magnify your thoughts, and make them more important to you, by keeping them with you in your wallet or purse," Petty said.

But how important is the physical action of throwing these thoughts away or keeping them in your pocket? To find out, the researchers conducted a third experiment using computers. In this case, 78 Spanish college students wrote their thoughts in a computer word-processing document. Some later used a mouse to drag the file into the computer recycle bin, while others moved the file to a storage disk.

Just as in the previous studies, participants made less use of negative thoughts that they had trashed -- by dragging them to the recycle bin -- than did those who saved the thoughts by transferring them to a disk.

In one other condition, some participants were told to simply imagine dragging their negative thoughts to the recycle bin or saving them to a disk. But that had no effect on their later judgments.

"The more convinced the person is that the thoughts are really gone, the better," Petty said. "Just imagining that you throw them away doesn't seem to work.

"Of course, even if you throw the thoughts in a garbage can or put them in the recycle bin on the computer, they are not really gone -- you can regenerate them. But the representations of those thoughts are gone, at least temporarily, and it seems to make it easier to not think about them."

Petty said the researchers plan to see if this technique could work to help people who have recurrent negative thoughts that are intrusive and bothersome, such as thoughts about the death of a loved one.

"It is often difficult to get rid of these thoughts. We want to find out if there is a way to keep those thoughts from coming back, at least for longer periods of time."

The study was supported by grants from the U.S. National Science Foundation and the equivalent agency in Spain.