Every single day, you take several IQ tests. You just aren't aware of them.
Did you look both ways before crossing the street? Did you get a flu shot? Did you buy that $4 organic banana? These are all IQ tests, and the result is either pass/fail. Occasionally, flunking one of these daily IQ tests has very real consequences.
The CDC reports that, in August 2016, at least 17 people in Colorado flunked an IQ test when they consumed raw milk and became sick. Milk samples and patient samples both tested positive for antibiotic-resistant Campylobacter jejuni, which causes vomiting and diarrhea.
Thankfully, they learned from this experience. Just kidding. The CDC says, "Although [individuals] were notified of the outbreak and cautioned against drinking the milk on multiple occasions, milk distribution was not discontinued."
That's not just flunking an IQ test. That's like getting kicked in the face by a horse, then tickling its rear end one more time just for fun.
Pasteurization Is a Triumph of Public Health
In Colorado, it is illegal to sell raw milk. Though I once endorsed that policy, I don't anymore. I believe adults should be free to put whatever they want in their bodies, and Darwin can sort things out.
I will, however, continue to relentlessly mock anyone who drinks raw milk. There is no nutritional justification for it and plenty of scientific evidence against it.
It isn't an exaggeration to claim that pasteurization has saved millions of lives. Before the invention of pasteurization, it was fairly common for people to get sick and die from eating contaminated food. Milk alone was known to spread typhoid fever (Salmonella), diphtheria, scarlet fever (Streptococcus), bovine tuberculosis, and even anthrax. Before widespread vaccination, polio could spread in milk.
This grim reality was reflected in the top 10 causes of death in the U.S. in 1900, the top three of which were due to infectious disease: pneumonia/influenza, tuberculosis, and diarrhea/gastroenteritis. Diphtheria was #10.
However, as public health improved, deaths from infectious disease fell. According to Neatorama, which has published a history of pasteurization, infant mortality in NYC fell from 273 per 1,000 live births in 1885 to 94 per 1,000 in 1915. One of the reasons was pasteurization.
The Paradox of Progress
Today, consuming raw milk or cheese is a senseless health risk. The CDC estimates that the risk of becoming sick from unpasteurized dairy products is 840 times higher than from pasteurized dairy products. So, why do people do it?
Because people take our public health triumphs for granted. In our modern society, we have very little to fear. Thanks to pasteurization, our food is safe; thanks to chlorination, our water is clean; and thanks to vaccination, our lives are (largely) free of contagious disease. And as an added bonus, violence is at a globally historic low. Anyone born in a developed country can expect to live into his 70's or 80's.
Completely ignorant of this history, some people have convinced themselves that the "old fashioned" way of doing things was better. In reality, the old fashioned way killed people, which is why society modernized.
Those who insist on rejecting that will have to grapple with the driving force of natural selection.