There are lots of products that we use because we think they are going to affect our body in some way. When we're tired, we might drink coffee or Red Bull to make us more alert. When we're in pain, we might pop a few Advil to make the pain go away. For all of these products, it takes some time for them to have an effect.
How do we judge how long it takes for them to work?
An interesting paper by David Faro in the August, 2010 issue of the Journal of Consumer Research suggests that judgments of how long it will take a product to work are affected by our beliefs about the effectiveness of the product. The more effective we think the product is, the less time that we think it will take for the product to work.
For example, in one study, Faro had people chew gum and then do a test of alertness that required them to respond as soon as a message appeared on a computer screen. Everyone was told to expect that chewing gum helps to increase alertness. One group of people was also told that practicing alertness tasks can improve performance on them. When people performed the alertness task, they were all given feedback showing them that their performance improved as they went along. So, the people who were told only that gum increases alertness should think that the gum affected their performance. The people who were told that gum increases alertness and that practice on the test makes them better at it should be less sure whether the gum was the reason they improved.
The group that was told only about the gum had a stronger belief that the gum affected their performance than those who also thought that practice could improve their performance. So, the experimental procedure affected people's belief about the effectiveness of the gum.
People also had to judge how quickly they thought the gum had its affect. People who believed that the gum was effective in increasing alertness thought it worked about 30 seconds faster than those that thought that practice on the test could also help performance.
What impact does this belief in the speed of performance have on future behavior?
One effect of believing that a product works is that it makes people resistant to other products that might have the same benefit. In this study, after people performed the alertness test, they were told that there are energy bars that could also increase alertness. Those people who thought that chewing gum was effective at increasing alertness were less likely to want to switch to an energy bar than people who thought gum was not that effective.
In addition, people in this study were told they were going to perform a second alertness test. They were told that they could have a second piece of gum before that test, and were asked how long before the test they wanted to start chewing the gum. Those people who had the strongest beliefs about the effectiveness of the gum wanted to start chewing it closer to the start of the test than those who had weaker beliefs about its effectiveness. That is, the belief that the gum was effective came along with the belief that it would be fast-acting.
This collection of results is interesting. Many products require some amount of time to be effective. If you mistakenly decide that the product will work more quickly than it actually does, you may not leave enough time for it to become effective. Thus, believing a product will work may lead to behaviors that reduce the actual effectiveness of the product.
This finding suggests that it is better to develop specific routines for using products that will help you maximize their effectiveness. For example, many people use caffeine to stay alert. However, it takes 30-45 minutes for caffeine to have its maximum impact. If you mistakenly estimate that it will work more quickly, then you may not drink your coffee far enough in advance of the need for it to allow it to influence your performance. Instead, it is better to determine when a product (like coffee) will be most effective, and to build a specific routine around using it to make sure that it is most effective for you.
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