"Thought-stopping" (which is just what it sounds like — you stop thinking a thought) was once a common stategy that therapists taught their clients. Actually, some therapists still do.
But in the late 1980s Dr. Daniel Wegner and his colleagues weren't so sure about this technique, so they conducted an experiment to learn more about suppressing thoughts.
The experiment had two parts, each lasting 5 minutes. Participants were told to report all of their thoughts out loud as they had them, and if they thought or said "white bear," they had to ring a bell.
One group of participants was told to not think of a white bear for the first 5 minutes and then to think of a white bear as much as they want during the second 5 minutes.
The other group of participants was told the opposite: to think about a white bear as much as they want for the first 5 minutes and then to not think of a white bear during the second 5 minutes.
The results were that participants were unable to follow the instruction to not to think of a white bear — on average they rang the bell indicating that they had thought or said "white bear" more than once per minute.
And, participants in the group who were told to not think of a white bear for the first 5 minutes? When they were told that they could think of a white bear for the second 5 minutes, they thought about a white bear much more often compared to participants in the group who were told they could think of a white bear during the first 5 minutes. This was called the "rebound effect."
From this experiment and his supporting work, Wegner developed his "ironic process theory:"
"When we try not to think of something, one part of our mind does avoid the forbidden thought, but another part "checks in" every so often to make sure the thought is not coming up—therefore, ironically, bringing it to mind."
(quote from the American Psychological Association)
(You can read more about the experiment and its implications and application at Scientific American.)
So when you're experiencing a thought that is unpleasant, unhelpful, or even distressing, don't get upset with yourself when you can't make that thought stop. Our brains just don't work that way.
There are many other strategies that can help, and they don't ask you to "stop thinking that thought." My next post will introduce you to one of those techniques, so be on the lookout!