The Nevada Sagebrush

Use critical thinking skills to avoid believing common myths

Monday, November 30, 2009 - 1:23 AM

Barry Belmont

With our bellies almost recovered from their Thanksgiving fills and our minds shaking off that pleasant numbness that accompanies familial comforts, we’ve reached the unfortunate time that comes between having learned a lot this semester and having to learn that little bit more to prepare us for the final.

But this seems to always be our state in life: knowing just enough to know what we have to learn next. Having spent Thanksgiving weekend away from the university community and out “in the real world,” I had the chance to interact with people more set in their ways; people less likely to want to learn that little bit more.

Perhaps the quip I overheard most while waiting in line, sipping hot cocoa in cafés or stuffing stuffing as far in as it’d go, was the one about that chemical in turkey that makes you sleepy. Trip-toe — tryptu — trip-to-something.Tryptophan.

When someone throws out a scientific-sounding word with hesitation, my ears prick up and I become a tad skeptical of the semi-plausible, semi-outlandish claim that accompanies it.

I first heard this staple of holiday wisdom early in my childhood, before my critical thinking muscle was sufficiently developed, and hearing it again so many years later threw my baloney detector into overdrive.

Investigating this pernicious little myth is not just an academic exercise. Rather, separating the truths, half-truths and misconceptions of this simple case will demonstrate the importance of thinking critically and relying on evidence, and show how even the smallest quasi-facts can distort our reasoning.

“Postprandial somnolence” is the overly fancy term for the sleepiness that occurs after ingesting a large meal. The evolutionary reasoning behind this concept is fairly straightforward. If you’ve spent all day hunting and gathering, it makes no sense to get sleepy before eating, but it is perfectly reasonable to expend as few calories as possible digesting the food you have eaten.

However, this phenomenon is not the result of the oft-toted mystery chemical “tryptophan.” In fact, tryptophan is just a plain old amino acid. It is in a lot of foods, from chocolate to yogurt to sesame seeds, and, yes, in large doses has been experimentally shown to cause sleepiness. But there’s not enough in an entire turkey to cause drowsiness, let alone the small amount any particular person eats.

In fact, post-feast sleepiness is likely caused by two things: the large amount of food eaten and the huge intake of carbohydrates, which boosts insulin levels (which in turn causes some interesting biochemical reactions).

“So what?” you may be asking yourself. “What’s the big deal? So what if I believe in some little falsity? It doesn’t hurt anybody.”

But how can one ever justify this type of believing-what-you-hear reasoning? Did you hear the one about using 10 percent of your brain? Or the one about pigeons exploding after eating rice? Alligators in New York City sewers? Intelligent design? How can your opinion on anything be respected if you so easily fall victim to faulty beliefs?

Thus, though it may be a constant struggle, we must ever be on guard against superstitions, urban legends, pseudoscience and all types of poor thinking if we are to make informed and meaningful decisions. We must always know enough to know what to learn next.

Barry Belmont studies mechanical engineering and biology. He ate a wonderful Thanksgiving dinner with his family, where he bored them with his science talk. Reach him at perspectives@nevadasagebrush.com.