Are Boys Getting Dumber While Girls Get Smarter?

A new study has been published with some startling news: pregnant mothers who drink fluoridated water have babies with lower IQs. More accurately, they have baby boys with lower IQs. But if they have a girl, their baby will have a higher IQ. Here’s the basic table:

A 1 milligram increase in maternal urinary fluoride levels was associated with a decrease of 4.49 IQ points in boys and an increase of 2.40 IQ points in girls. This seems implausibly large, doesn’t it? But I can think of at least one crude way to check it. In 1950 virtually no water in the US was fluoridated. Today, fluoridated water reaches more than 70 percent of the population. At a minimum, this suggests that over the last 70 years the IQ levels of boys and girls (a) should have gone down, and (b) should have diverged by about 7 points. Has this happened?

In a word, no. Overall IQ scores in the United States have increased since 1950 and that steady upward trend has continued at least through 2014. And I’m unable to find any evidence that the mean scores of boys and girls has differed by more than one point or so during this entire period. Obviously lots of other things have been going on at the same time, so this doesn’t prove anything. But it sure puts a high burden on anyone claiming an IQ effect that affects boys and girls differentially by 7 points.

THE FACTS SPEAK FOR THEMSELVES.

At least we hope they will, because that’s our approach to raising the $350,000 in online donations we need right now—during our high-stakes December fundraising push.

It’s the most important month of the year for our fundraising, with upward of 15 percent of our annual online total coming in during the final week—and there’s a lot to say about why Mother Jones’ journalism, and thus hitting that big number, matters tremendously right now.

But you told us fundraising is annoying—with the gimmicks, overwrought tone, manipulative language, and sheer volume of urgent URGENT URGENT!!! content we’re all bombarded with. It sure can be.

So we’re going to try making this as un-annoying as possible. In “Let the Facts Speak for Themselves” we give it our best shot, answering three questions that most any fundraising should try to speak to: Why us, why now, why does it matter?

The upshot? Mother Jones does journalism you don’t find elsewhere: in-depth, time-intensive, ahead-of-the-curve reporting on underreported beats. We operate on razor-thin margins in an unfathomably hard news business, and can’t afford to come up short on these online goals. And given everything, reporting like ours is vital right now.

If you can afford to part with a few bucks, please support the reporting you get from Mother Jones with a much-needed year-end donation. And please do it now, while you’re thinking about it—with fewer people paying attention to the news like you are, we need everyone with us to get there.

payment methods

THE FACTS SPEAK FOR THEMSELVES.

At least we hope they will, because that’s our approach to raising the $350,000 in online donations we need right now—during our high-stakes December fundraising push.

It’s the most important month of the year for our fundraising, with upward of 15 percent of our annual online total coming in during the final week—and there’s a lot to say about why Mother Jones’ journalism, and thus hitting that big number, matters tremendously right now.

But you told us fundraising is annoying—with the gimmicks, overwrought tone, manipulative language, and sheer volume of urgent URGENT URGENT!!! content we’re all bombarded with. It sure can be.

So we’re going to try making this as un-annoying as possible. In “Let the Facts Speak for Themselves” we give it our best shot, answering three questions that most any fundraising should try to speak to: Why us, why now, why does it matter?

The upshot? Mother Jones does journalism you don’t find elsewhere: in-depth, time-intensive, ahead-of-the-curve reporting on underreported beats. We operate on razor-thin margins in an unfathomably hard news business, and can’t afford to come up short on these online goals. And given everything, reporting like ours is vital right now.

If you can afford to part with a few bucks, please support the reporting you get from Mother Jones with a much-needed year-end donation. And please do it now, while you’re thinking about it—with fewer people paying attention to the news like you are, we need everyone with us to get there.

payment methods

We Recommend

Latest

Sign up for our free newsletter

Subscribe to the Mother Jones Daily to have our top stories delivered directly to your inbox.

Get our award-winning magazine

Save big on a full year of investigations, ideas, and insights.

Subscribe

Support our journalism

Help Mother Jones' reporters dig deep with a tax-deductible donation.

Donate