Skeptoid answers some more questions from students. Send yours in today!

by Brian Dunning

Filed under Feedback & Questions

Skeptoid Podcast #119

September 16, 2008

Podcast transcript | Subscribe

Listen:

https://skeptoid.com/audio/skeptoid-4119.mp3

Once again we're going to open the email folder and answer some questions from students. If you're a student of any age, and you have a question you'd like me to answer, I'd love to hear from you. Just go to Skeptoid.com and click on Student Questions to see how to record and submit your question to me. It's really easy, and all you need is access to any computer with a microphone. Today's questions cover body searches, theta healing, dreams coming true, marijuana use, and the genetic foundations of homosexuality. Let's dive right in.

Hi, my name is Avi Steiner, and I was wondering: Is the controversy over full-body searches in airlines merited?

There are many branches to this question, and I'm not quite sure which you're most interested in. Two that are within the scope of Skeptoid to address are the statistics of whether full body searches actually prevent air piracy, and whether the image clarity of the latest imaging techniques are actually as revealing as some say they are. As far as this question goes, that's a big yes. It's called Backscatter X-Ray and it produces images that are exactly what every 10-year-old boy hoped his Cracker Jack X-Ray Spectacles would produce. Susan Hallowell, Director of the Transportation Security Administration's research lab, famously allowed a picture of herself that leaves little to the imagination to be released to the media, and if that doesn't send you scrambling to Google's image search, I don't know what will.

If your concern is whether body searches have been proven to reduce air piracy, the answer's not as clear. You may be tempted to answer "Well duh, of course it helps, because the hijackers can't bring weapons on board." But this thought experiment may be all you have to go on, because there's insufficient data to draw any conclusions from the real world. Most such incidents happen in countries where security is minimal, but there are far too many other variables at play to conclude that the low security level was the reason that the piracy acts took place from those particular airports. The Aviation Safety Network lists six fatality hijackings that took place in 2007, four in Africa and two in Turkey. Are body searches the reason these hijackings didn't happen in the United States? It could also be that these particular hijackers had less to gain by choosing a flight from Colorado Springs to Orlando.

Hi Brian, My name is Mia, from Swinburne University, Melbourne, Australia. I want to know what your take is on the mystical Theta Healing. I have a friend who is very much into it but I get the feeling that there's not much evidence behind what it claims to do. What do you think?

Theta healing is just another random "roll-the-dice and invent a New Age healing technique" based on some imaginary energy field. This one was invented in 1995 by a self-described "intuitive reader" who believed that she could project theta waves from her brain which would instantly heal the patient. Theta healing claims to immediately and completely cure cancer, severe injuries, and even psychological and financial problems.

In fact, a theta wave is not an energy field or a type of energy at all. It's simply the name of one type of waveform on an electroencephalogram. When an EEG shows a sine wave with a period of between 4 and 8 Hertz, neurologists designate that as a theta pattern. This waveform is observed when the subject is asleep or at rest, and in some types of learning involving short term memory.

Probably what happened is that this "intuitive reader" heard the term "theta wave", misinterpreted it to mean a type of mystical energy field generated by the brain; and then erroneously put two and two together when one of her customers reported some kind of positive experience. If you look at any web page about theta healing, you'll see all kinds of vaguely scientific sounding words thrown out there in meaningless disarray. There's nothing plausible about it and no description specific enough to test, but unfortunately, unscientific laypeople are all too often ill-equipped to recognize that such technobabble on a web page is baseless.

I'm David Alexander, a university student in Ottawa, Canada, and I myself have had quite a few dreams I recall very vividly, and discover myself weeks or months later in a situation that (as far as I could tell) matches my prior dream almost exactly to the point of being able to predict with certainly what is about to happen. My question is: what would you tell me about these experiences I have, in light of the sheer improbability of these types of things occurring?

Although I can't speak authoritatively on your specific case, I can tell you that what you describe as sheer improbability, when applied to all the dreams, thoughts, and daily experiences that a person has, surprising coincidences become not only probable, but inevitable. The law of large numbers requires that, on average, of the one million waking events you experience in a month at the rate of about one a second, one of them will be a one-in-a-million coincidence. You seem to be someone who pays a great deal of attention to matching his dreams to later experiences, and so you are by definition a walking case of confirmation bias. How many dreams have you had that did not later come true? Most of them. Of each dream that did come true, how much of the dream came true? All several hours of it, or only one of its thousands of bits? Considering that your dreams have only your life experience to draw from for their material, it's almost inconceiveable for your dreams to not match a substantial part of what happens in your daily life.

I'm sure you can point to half a dozen cases where the match was too incredibly strange to have been a coincidence. Well, so can everyone, the difference is that most of us don't pay as much attention to it as you and so we quickly forget. I only remember one such case, but I know there have been others, I just forgot about them. Don't allow yourself to confuse confirmation bias — our tendency to remember the few hits and forget the vast majority of misses — with the impression that hits were more prominent than they really were.

Hello, this is Evan from Stratford Ontario. I was wondering what are the real effects of regular marijuana use?

Well, I'll avoid the obvious assumption about why you're asking, and instead cut to the chase. For most light users, the risks of long term pot smoking are probably not worth worrying about. The risks of driving your car or smoking cigarettes are more substantial concerns. About 1 in 25 adults smoke marijuana at least once a year, with few long term effects. Short term effects can be a bigger concern. Don't plan to drive that day; don't put yourself in a situation where you might make a jackass out of yourself; don't get fired for being high on the job. Use good sense.

Heavy usage, or even a rare heavy usage, can absolutely be a problem. I once ate some brownies that I didn't know were full of pot, then drove home. I passed out on the freeway, and came to driving on the dirt shoulder at 70 mph, blind and paralyzed on my left side. It took several days to recover fully, and you can bet I went to the hospital where they ruled out all the other possible causes they could think of. You can also bet that I'll never touch the stuff again. Don't ever OD, and don't let your friends OD.

You've already demonstrated the best precaution, which is to ask before you leap. Impress the heck out of your doctor by asking him. Look it up on the web. Sites like WebMD are great places to get decent, general, consumer level information about health topics like this, and you'll see that WebMD does list potential long term problems like gum disease, changes in blood viscosity, and pregnancy concerns. No drug is completely safe, but then again, what is?

I'm Kevin Mellis, I'm 18, and I'm a student at the University of La Verne. My question is this: Homosexuality is popularly conceived as innate in a person's personality. Is there any scientific research regarding the veracity of this commonly held belief?

Yes there is. Despite Newsweek and the Wall Street Journal's best efforts to promote sensationalism through misleading headlines, one thing that is very clear to geneticists is that there is no "gay gene". The idea got its start in 1993 when Science published a study of homosexuality and genetic frequencies among familes. It was complicated, and was grossly and irresponsibly oversimplified into the "gay gene" by the media. New research is published pretty often, and about the only consensus that's displayed is that it seems likely that homosexuality has a combination of genetic, other biological, and environmental causes. If you read anything that claims to have found a single or clearly identified cause of homosexuality, you have very good reason to be skeptical of that source.

If you're a student and you want to hear my take on something, come to Skeptoid.com and click on Answering Student Questions. Get a quick answer on some urban legend, conspiracy theory, or paranormal phenomenon you're curious about. I'd love to hear from you, and answer your question on a future show.



By Brian Dunning

Follow @BrianDunning