Good Science, Bad Science
I was severely disappointed with the August issue of Discover. If one defines intelligence as critical, evidence-based thinking, then your editorial board and reporters are deficient in this characteristic. Your articles "Worrying About Milk" and "Heresy" are devoid of the applications of scientific thinking that must be exercised by any magazine purporting to be a scientific publication. It appears that you do not appreciate the difference between causation and correlation. I expect at least that from my sources of scientific information. These articles should have appeared in journals that report advances in the fantasy world of ESP, where accurate scientific studies are not necessary.
Robin Oxman, M.D.
Huntington Beach, California
Kudos on your daring August issue! Would that all science magazines reserved some space for "news that challenges comfortable ideas and accepted wisdom." The importance of agitation in the scientific community (often funded by private interests) is not lost on me; any science that refuses to accept a challenge is not good science. Congratulations on giving a voice to controversial researchers.
As a physician and nurse, I agree that discouraging everyone from drinking cow's milk is a smart idea. Dairy is implicated in many serious health problems: heart disease, ovarian cancer, childhood-onset diabetes, colic, breast cancer, and asthma.
In June 1999, a dairy executive at the "Calcium Summit" in Washington, D.C., bragged that his industry especially targeted moms, kids, and college students. It's vital for those groups, and the rest of us, not to swallow all those paid celebrity milk-mustache ads and clever "Got Milk?" pitches and realize that no one needs to drink cow's milk to ward off osteoporosis and bone breaks. Yes, we all require calcium. But we can easily meet our needs through fortified fruit juices, beans, calcium-set tofu, and leafy green vegetables. Other bone-protecting steps include not smoking, minimizing sodium intake, avoiding animal protein, doing weight-bearing exercises, and getting vitamin D from a few minutes of daily sun exposure, fortified breakfast cereals and soy milks, or a multivitamin supplement.
Patrice Green, M.D.
So T. Colin Campbell thinks it's strange that we're the only species that suckles the milk of another species? That's a great sound bite, but it has no significance in scientific inquiry. Did he do a controlled study that showed rats who drank milk from a blue whale had more cancer than those who ate soybeans from a farmer's bin? We're also the only species that plays Mozart; that doesn't necessarily make it good or bad for our health.
Most of Campbell's conclusions are based on poor cross-cultural studies. Even the Harvard Nurses' Health Study is suspect because respondents reported their own dietary habits, and it seems to me that people tend to exaggerate their consumption of good foods (milk?) when asked about their eating habits.
Finally, when will dietary researchers in this country realize that people do not eat what they are told to eat? They eat what they like. Farmers grow certain foods because over the years consumers have spoken at the checkout line. To imply that farmers and government nutritionists are foisting unhealthy foods on an unsuspecting public just feeds into the current thinking that we're not responsible for our own actions anymore.
Newport, New York
I am a retired veterinarian, having doctored horses and cattle for 25 years. Your article on milk brought back many memories. When farmers kept a milk cow on the farm for the weaner calves, there were few digestive problems. But when no dairy cows were available, the farmers bought milk for the calves to drink.
I soon found that these calves could not digest pasteurized, homogenized milk. Homogenization breaks the fat globule into such small bits that it doesn't curd in the stomach and passes directly into the small intestine, where it created a severe inflammation in the calves. I treated them with goat's milk, which has the largest fat globule of any milk found on the farm. Most of the calves I treated made a quick recovery.
I, too, drank milk on the farm, and I never had any adverse effects. But in college I started drinking store-bought milk, which acted like poison on my system. Fifty years later, a friend with a milk cow offered me some milk. I accepted, and for three years now I've been drinking milk as I did on the farm, with no adverse side effects.
Earl D. Smith, D.V.M.
I greatly appreciated that Brad Lemley, the author of "Heresy," identified Rupert Sheldrake's body of work with David Bohm's interpretation of quantum theory. However, Lemley greatly distorted the plausibility and degree of acceptance that Bohm's ideas enjoy.
The experiments of Alain Aspect noted by Lemley hardly count as strong support for Bohm. In fact, they were widely recognized as settling the debate over "hidden variable" explanations of quantum theory in favor of the "Copenhagen" interpretation, [which states that the act of observing affects the nature of reality at the subatomic level].
This reading of quantum mechanics eliminates the need for hidden variables like those postulated by Bohm (and of course Sheldrake's "morphic fields" are hidden variables writ large). It is true that Bohm's interpretation can be made consistent with the findings, but only after violating relativity theory, a problem the Copenhagen reading does not share.
While I for one have little time for Sheldrake's ideas, I applaud Discover for giving unusual notions like this a public hearing. Mainstream science is ill served by presenting itself dogmatically, as some of Sheldrake's critics do.
Kudos on your article on Rupert Sheldrake. His "heresies" are knowledge ahead of its time. Current science may look at DNA as the "root of life," but DNA of and by itself is as lifeless as the coils, condensers, and wiring in a TV set. You don't find the picture by looking at the wiring. Raw DNA is merely the tuning mechanism that resonates to a particular morphic field, which is unfolded and out-pictured into a biological life-form.
San Francisco, California
Neither Nature Nor Nurture?
Your article about Mark Flinn's study of cortisol levels in Dominican children ["Family Matters," August] gave readers the misleading impression that Flinn's results are in conflict with my theory of child development. In fact, Flinn and I have great respect for each other's work. Our views are not in conflict because we are talking about different things.
My book is about the long-term effects of childhood experiences not playground quarrels of the sort described in the article but (for example) those of the child who is subjected to day-to-day denigration by his peers over a period of years. Being yelled at by one's parents is undoubtedly stressful, but the evidence summarized in my book indicates that it has no measurable effects on adult personality. This makes evolutionary sense, because children are not destined to spend their adult lives with their parents.
Why do children have some of the same personality strengths and weaknesses as their parents? The answer (based not just on studies of identical twins reared apart but on hundreds of studies, using a variety of methods) is simple: heredity. My theory was designed to answer a more difficult question: How do we account for the differences in personality that can be explained neither by heredity nor by "nurture" (the way children are treated by their parents)? My answer has to do with the experiences children have outside the parental home, which is where they are destined to spend their adult lives.
Judith Rich Harris
Author, The Nurture Assumption
Middletown, New Jersey
In "Why Has Our Weather Gone Wild?" (June), we should have credited NOAA/GFDL, from a report by T. Delworth, K. Dixon, and T. Knutson, as the source for the map that appears on page 76.
On page 40 in the August Sky Lights, we misidentified the Apollo 12 astronaut in the photo as Pete Conrad. He is actually astronaut Alan Bean.
In "The Panther Mountain Crater" (August), we stated on page 59 that iridium is a chemical produced in the heat and pressure of meteorite impacts. Iridium is an element often found in meteorites and spread on impact.