US Gained a Decade of Flynn-Effect IQ Points After Adding Iodine To Salt

cold fjord writes "I wish it was always this easy. Business Insider reports, 'Iodized salt is so ubiquitous that we barely notice it. Few people know why it even exists. Iodine deficiency remains the world's leading cause of preventable mental retardation. According to a new study (abstract), its introduction in America in 1924 had an effect so profound that it raised the country's IQ. A new NBER working paper from James Feyrer, Dimitra Politi, and David N. Weil finds that the population in iodine-deficient areas saw IQs rise by a full standard deviation, which is 15 points, after iodized salt was introduced.... The mental impacts were unknown, the program was started to fight goiter, so these effects were an extremely fortunate, unintended side effect.'"

Comments

The question you are all asking...

[Megane]

What is the Flynn Effect?

Not the only public health benefit.

[Anonymous Coward]

Simply meeting the basic needs of the general public brings huge gains.

There used to be a stereotype that all southerners were lazy and terrible workers. Turns out they were really just riddled with parasites (That train your energy and make you tired) Basic sanitation (Even things a simple as proper outhouses dug deep enough) solved that problem amazingly well. Many poor nations struggle with this problem today, however.

The Army started school lunch programs because malnourished children were growing up stunted and short (among other health problems), and made for awful soldiers.

Re:Not the only public health benefit.

[Intropy]

I believe you are referring to hookworms, which were found in an estimated 40%-70% of people living in the Southern US in the early 1900s in sufficient amounts to cause disease. They cause anemia and fatigue. They're expelled in feces, and can live in soil for a while. The problem was them digging out of outhouses through the soil and finding their way into people walking around barefoot. The solution was to dig deeper outhouses, so that the hookworm couldn't live in the soil long enough to reach the surface, and to wear shoes. On the flip side, there's serious current research into using small-scale hookworm infestation as a treatment for inflammatory diseases, including crohn's and multiple sclerosis.

Re:Not the only public health benefit.

[ShanghaiBill]

What kind of parasites, and why did they have more of them than damnyankees? Serious question.

A number of energy and grown sapping diseases, such as malaria and yellow fever, were common in the American South in the 19th century, but uncommon in the North. But the biggest culprit was probably hookworms, which cause "intellectual, cognitive and growth retardation". Average IQ in the South increased significantly as hookworms were eradicated in the early 20th century.

We might get another gain if we eradicate toxoplasmosis, a parasite spread by cats. It is believed by some to depress intelligence and novelty seeking behavior in humans.

Re:Gained I.Q. with Iodized salt -

[cold fjord]

Maybe not.

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