Common Wisdon - Not Always So Wise

I am a fan of Skeptic Magazine, and subscribe to the email newsletter, eSKEPTIC. In the last newsletter I recieved, there are a really interesting article on Myths in Popular Psychology. Please note the term, popular psychology. Sometimes popular doesn't mean it's based in science, or that it might have been a popular scientific idea at one point, but further reseach has debunked it.

Anyway, some of these I knew were myths, but others suprised me.

Myth: We only use 10% of our Brains

There are several reasons to doubt that 90% of our brains lie silent. At a mere 2–3% of our body weight, our brain consumes over 20% of the oxygen we breathe. It’s implausible that evolution would have permitted the squandering of resources on a scale necessary to build and maintain such a massively underutilized organ. Moreover, losing far less than 90% of the brain to accident or disease almost always has catastrophic consequences. Likewise, electrical stimulation of sites in the brain during neurosurgery has failed to uncover any “silent areas.”

Myth: Low Self Esteem is the cause of psychological problems.

Don't get me wrong - I think positive self-esteem is important, but I think that giving kids an opportunity to try things and succeed builds a positive self image, and debriefing and making sense of mistakes helps kids deals with the emotional bumps and bruises of growing up. But I really like the reference to school performance - this is a classic example of being careful not to confuse correlation with causation.

Research shows that low self esteem isn’t strongly associated with poor mental health. In a comprehensive review, Roy Baumeister and his colleagues canvassed over 15,000 studies linking self-esteem to just about every conceivable psychological variable. They found that self-esteem is minimally related to interpersonal success, and not consistently related to alcohol or drug abuse. Moreover, they discovered that although self-esteem is positively associated with school performance, better school performance appears to contribute to high self-esteem rather than the other way around. Perhaps most surprising of all, they found that “low self-esteem is neither necessary nor sufficient for depression.”

Myth: The Polygraph Test is an Accurate Means of Detecting Lies

This one really surprised me. I remember as a teenager watching shows like Maury and Jerry Springer who both use polygraph tests repeatedly to create drama on their shows (yes, I used to indulge in trashy TV as a teenager, surprise, surprise). I used to be soooooo amused by the people who were "caught in a lie" on a polygraph test and still maintained their innocence. I mean, really, who did they think they were? However...

If a polygraph chart shows more physiological activity when the examinee responds to questions about a crime than to irrelevant questions, at most this difference tells us that the examinee was more nervous at those moments. Yet this difference could be due to actual guilt, indignation or shock at being unjustly accused, or the realization that one’s responses to questions about the crime could lead to being fired, fined, or imprisoned. Thus, polygraph tests suffer from a high rate of “false positives” — innocent people whom the test deems guilty. As a consequence, the “lie detector” test is misnamed: It’s really an arousal detector. Conversely, some individuals who are guilty may not experience anxiety when telling lies. For example, psychopaths are notoriously immune to fear and may be able to “beat” the test in high pressure situations, although the research evidence for this possibility is mixed.

There is a whole lot more in the article, including why these myths are so popular. You can read the whole article here.