Scientific Misconceptions

Scientific Misconceptions

The term “Fake news” has received attention recently because of the circulation of false and “alternative” facts. It has become such a concern that two weeks ago Google introduced a new policy which attempts to limit the amount of “bad publishers” who pop up when you search for news. In a similar step Facebook has updated their algorithms in an effort to weed out and remove false news stories. While social media and search engines are only just entering the fight against “fake news” this is a problem that scientists have dealt with for years. Some of the most famous examples of false scientific claims include statements like “vaccines cause autism” (they don’t) and “evolution is only a theory” (It is, but in science a theory doesn’t mean it’s not real). Unfortunately it would take more than one article to discuss these politically charged topics, so instead here are some slightly less controversial, but nonetheless well-known and incorrect, scientific misconceptions.

Different parts of the tongue taste different things

If you think back to science lessons in primary or secondary school you may have seen a “tongue map” which showed different areas of the tongue and suggested they separately taste either bitter, sour, salty or sweet. While those are the primary tastes our tongues respond too, the truth is that there is no one area on the tongue responsible for tasting them. This misconception comes from a paper written by a Harvard psychologist, Edwin G. Boring (yes, it’s his real name). This paper had been translated from a German paper, Zur Psychophysik des Geschmackssinnes, written in 1901. Due to either translation errors or misinterpretation of the data, the English translation made the suggestion that each part of the tongue tasted only one of the basic flavours. In fact, the original paper described only minuscule differences in detection levels across the tongue. Further down the line, this work was taken out of context and the “tongue map” was drawn and written up in textbooks; since then this diagram and misunderstanding has been passed on. To counter the claim a study published in Nature in 2006, confirmed that while receptors for the basic tastes are found in specific types of cells, these cells are not limited to one area and are spread throughout the tongue.

We only use 10% of our brains

This science-myth has been propagated through popular culture by movies like Lucy and Limitless, which explore the possibility of unlocking the full potential of the human brain.  One of the key problems with this, is the phrasing – what does it mean by 10% of our brain? Is it suggesting that we only use one out of every ten neurons, or that at any given time only 10% of our brain is active? Either way the origins of this misconception are unclear, it is thought that it stems from the theories proposed by Harvard psychologists William James and Boris Sidis in the 1890s. These researchers investigated child prodigies and, in front of an audience, made the statement that “people only meet a fraction of their full mental potential”; which when comparing the average adult to a prodigy, is true. Later in 1936, in a preface to a book, writer Lowell Thomas re-described this theory; however he added a false percentage value, claiming “the average man develops only ten percent of his latent mental ability”. Since then this myth has continued to be passed on, however there are number reasons that it is false. From an evolutionary standpoint it is unlikely that we would have developed large brains if we weren’t going to use the entire thing. Likewise, even if neurons are not firing at a given point they are likely receiving signals from other neurons. This is reinforced by evidence from advanced Brain Imaging techniques, such as functional magnetic resonance imaging (fMRI). These studies have revealed that, even during sleep, all parts of the brain show some level of activity. Overall, claiming we only use 10% of our brain is both non-descript and a misconception.

We have five senses

If you ask the average member of the public, whether a child or adult, they would likely say that we have five senses; taste, smell, sight, touch, hearing (In case you forget what they were). It may prove controversial, but the truth is that humans have more than five senses and I’m not talking about extrasensory perception. The most commonly used, and simplest, definition of a sense is: “any system that consists of a group of sensory cells which respond to a specific physical phenomenon.” When considering this definition many of our body’s internal mechanisms fall under the classification of a sense. This includes a sense of balance, pain and proprioception; the latter means that your brain knows where all your body parts are. These kinds of senses are aptly named the “non-traditional senses”. Another key, but even more abstract, sense is the ability to determine the passage of time. Experiments have shown that, without consciously counting, people are able to tell when a specific amount of time has passed, within a margin of 3 seconds. Some would argue that these non-traditional senses don’t actually count, but it all depends on how you define a “sense.” Some people have argued that these other senses are just variations on the key five, or that they deserve their own unique classification. Unfortunately, the number of senses that we actually have is still uncertain; it is estimated that we have at least nine, potentially twenty. If you don’t like that level of uncertainty you can carry on saying we have five, but the truth is we have more, it’s just we can’t decide exactly how many more.

 

Steven Gibney

 

(Image courtesy of Michel Royon)

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