Don't Swallow Your Gum!: Myths, Half-Truths, and Outright Lies About Your Body and Health - Softcover

Dr. Aaron E. Carroll is an associate professor of Pediatrics and the director of the Center for Health Policy and Professionalism Research at the Indiana University School of Medicine.

Dr. Rachel C. Vreeman is an assistant professor of Pediatrics in Children's Health Services Research at the Indiana University School of Medicine and co-director of Pediatric Research for the Academic Model for the Prevention and Treatment of HIV/AIDS (AMPATH).

Aaron and Rachel's research has been featured in The New York Times, USA Today, The Los Angeles Times, Scientific American, Newsweek, and many other national publications. They have appeared on Good Morning America, CBS Evening News, and ABC News NOW.

Chapter One

Men with big feet have bigger penises

Have you ever noticed a man with particularly big feet and wondered if other parts of him were just as large? While some claim that a man’s penis size can be predicted by the size of his feet, others say that it’s the size of his hands or even his nose that really gives away the secret of what’s in his pants. This idea of comparing body parts to estimate hidden assets may have originated with discriminating shoppers, but it may also have its roots in real science. The Hox gene in mammals plays a role in the development of the toes and fingers, as well as the penis or clitoris. Given how rarely one hears “gene expression” mentioned along with the talk of penises and feet, it seems much more likely that this myth springs from our desire, as humans, to identify patterns—even when the pattern is not really there. We like to have explanations for things we see, and we like to group like things with like things (in this case, appendages on men).

Despite the similar genetic controls for these protuberances, men with big feet do not necessarily have bigger penises. While at first, the prospects for estimating penile length with a quick glance at a man’s feet seemed promising, science now shows us that this is not the case. A study of sixty men in Canada suggested that there was a weak—but statistically significant—relationship between penile length and both body height and foot length (remember—statistically significant doesn’t necessarily mean significant in real life). However, a larger study of 104 men, done by two urologists, Drs. Shah and Christopher, which measured penises when pulled to their longest lengths, found that shoe size and penis size were not correlated with one another. An even larger study called the “Definitive Penis Size Survey,“ which looked at 3,100 men, also found no relationship between shoe size and erect penis size. This was even when men reported their size, as opposed to direct measurement. And when men are asked to report the length of their own members... well, let’s just say that science also shows us that exaggeration routinely comes into play. Furthermore, the “Definitive Penis Size Survey” was never peer-reviewed or published in a scientific journal. We trust the results from Drs. Shah and Christopher the most, but this survey backs them up. Studies also show no link between finger length and penis size. You can look at a guy’s feet or hands all you want, but they won’t tell you anything else about how he measures up.

Excerpted from DON’T SWALLOW YOUR GUM! by AARON E. CARROLL and RACHEL C. VREEMAN

Copyright © 2009 by Aaron E. Carroll And Rachel C. Vreeman

Published in June 2009 by St. Martin’s Press

All rights reserved. This work is protected under copyright laws and reproduction is strictly prohibited. Permission to reproduce the material in any manner or medium must be secured from the Publisher.