Recently, I heard another iteration of something I find fascinating. A person complains that they can’t drink tea in the evening because the caffeine keeps them awake, but they don’t like the taste of decaf teas and herbals don’t suit them. What are they to do?
Then a tea shop eager to sell them some tea tells them that all they have to do is do a quick 30-second steep, which removes most of the caffeine, pour that out, and re-steep the recommended length for a great low-caffeine cuppa for the evening. The customer follows this procedure and voila! Evening cups of tea AND sleep ensue. Victory!
I’ve heard this story on a number of occasions and it always makes me laugh a little, as well as getting curious. Because as I’ve mentioned on other posts and in the TeaGeek wiki, the 30-second decaf thing is a common tea myth. A majority of the antioxidants come out in the first 30 seconds, but perhaps less than 10% of the caffeine. This is based on the results of a couple of tea studies (which, if you’re interested, you can find references to via the links earlier in this paragraph).
Why do I laugh and become curious? Because if you put the customer story and the tea science together, you have to ask a question: Given that the customer slept well after a process that as been shown NOT to remove much caffeine, what’s the explanation for this phenomenon?
Personally, I think it’s psychology. First off, I think that most people first blame any sleeping problems on any caffeine they might have had. Tea and coffee come first as perceived sources of caffeine, even though some chocolate desserts can have more caffeine than a cup of tea, and are regularly enjoyed in the evening.
Next, I think that the 30-second decaffeination ritual invokes a kind of placebo effect. The customer believes there is no caffeine in the tea. Maybe it actually helps decrease the effect of the caffeine that is present, in a similar way that college students get impaired reactions when drinking alcohol-free beer that they believe to be normal beer. Or perhaps it just helps the customer choose other reasons for troubled sleep–that chocolate cake, or stress, or noisy neighbors. After all, it couldn’t be caffeine because it had all been removed in the 30-second rinse.
Either way, it becomes easier to think that the caffeine-disrupted sleep problem has been solved. And this could happen even if nothing had changed at all.
Another thing to look at is whether something besides caffeine has changed. For example, I have had evening tea and slept like a baby (last night for example). Other times, I’ve had evening tea and slept poorly. It’s easy to remember the times when you sleep poorly after having tea, but there’s no reason to pay attention to whether you had tea late in cases where you sleep well. So the poor-sleep nights stick out in the memory, seeming to get a prominence not warranted by their actual frequency.
(There’s a term for this particular flavor of cognitive bias, but I can’t recall it at the moment. I do know it’s mentioned in Stumbling on Happiness by Dan Gilbert. It’s a fascinating read even if you’re not a tea geek. This same bias is why it seems that your line at the grocery store always goes slowest–when the line goes quickly, you don’t pay attention to it, but when it goes slow it sticks in your memory.)
Now, I’m not a psychologist and I don’t have the facilities to carry out the research that would be necessary to verify my hypotheses (sleep studies, testing caffeine extraction rates, etc.) but it seems likely that psychology plays a big role in how we perceive caffeine and its effects in ourselves. Of course, I’m open to other ideas about why so many people’s perceptions and experiences are at odds with the scientific evidence in this area. Leave a comment if you’ve got one!