The rejection of hard-won knowledge is by no means a new phenomenon. In 1905, French mathematician and scientist Henri Poincaré said that the willingness to embrace pseudo-science flourished because people know how cruel the truth often is, and we wonder whether illusion is not more consoling. Decades later, the astronomer Carl Sagan reached a similar conclusion: Science loses ground to pseudo-science because the latter seems to offer more comfort. A great many of these belief systems address real human needs that are not being met by our society, Sagan wrote of certain Americans embrace of reincarnation, channeling, and extraterrestrials. There are unsatisfied medical needs, spiritual needs, and needs for communion with the rest of the human community.
Looking back over human history, rationality has been the anomaly. Being rational takes work, education, and a sober determination to avoid making hasty inferences, even when they appear to make perfect sense. Much like infectious diseases themselves beaten back by decades of effort to vaccinate the populace the irrational lingers just below the surface, waiting for us to let down our guard.
Before smallpox was eradicated with a vaccine, it killed an estimated 500 million people. And just 60 years ago, polio paralyzed 16,000 Americans every year, while rubella caused birth defects and mental retardation in as many as 20,000 newborns. Measles infected 4 million children, killing 3,000 annually, and a bacterium called Haemophilus influenzae type b caused Hib meningitis in more than 15,000 children, leaving many with permanent brain damage. Infant mortality and abbreviated life spans now regarded as a third world problem were a first world reality.
Today, because the looming risk of childhood death is out of sight, it is also largely out of mind, leading a growing number of Americans to worry about what is in fact a much lesser risk: the ill effects of vaccines. If your newborn gets pertussis, for example, there is a 1 percent chance that the baby will die of pulmonary hypertension or other complications. The risk of dying from the pertussis vaccine, by contrast, is practically nonexistent in fact, no study has linked DTaP (the three-in-one immunization that protects against diphtheria, tetanus, and pertussis) to death in children. Nobody in the pro-vaccine camp asserts that vaccines are risk-free, but the risks are minute in comparison to the alternative.
Still, despite peer-reviewed evidence, many parents ignore the math and agonize about whether to vaccinate. Why? For starters, the human brain has a natural tendency to pattern-match to ignore the old dictum correlation does not imply causation and stubbornly persist in associating proximate phenomena. If two things coexist, the brain often tells us, they must be related. Some parents of autistic children noticed that their childs condition began to appear shortly after a vaccination. The conclusion: The vaccine must have caused the autism. Sounds reasonable, even though, as many scientists have noted, it has long been known that autism and other neurological impairments often become evident at or around the age of 18 to 24 months, which just happens to be the same time children receive multiple vaccinations. Correlation, perhaps. But not causation, as studies have shown.
And if you need a new factoid to support your belief system, it has never been easier to find one. The Internet offers a treasure trove of undifferentiated information, data, research, speculation, half-truths, anecdotes, and conjecture about health and medicine. It is also a democratizing force that tends to undermine authority, cut out the middleman, and empower individuals. In a world where anyone can attend what McCarthy calls the University of Google, boning up on immunology before getting your child vaccinated seems like good, responsible parenting. Thanks to the Internet, everyone can be their own medical investigator.
It's really kind of hard to tell, but it tends to remind me of the mind set of people who buy all of these "amazing" weight loss "wonder pills" and such that air in the wee hours of the morning on Infomercials.. They normally have some guy standing there in a white lab coat - that claims to be a doctor - and that's good enough for them.. Scary.. 
Why?? And honestly, how can you really think this is right?
