There’s a stupid, absolutely false myth circulating on the racist internet: the idea that black men disproportionately rape white women, and white men never rape black women. Again, this claim is demonstrably untrue.

And yet it’s popular enough, as the sociologist Philip Cohen noted in a recent blog post, to have turned into a repugnant meme:

Now of course, it’s not worth responding to every idiotic meme that circulates in the backwater swamps of the racist internet. But, as Cohen notes, this one seems to have become unusually viral. And we’re in an election year that racists have claimed as a victory for their violent imaginations. David Duke, America’s most famous ex-KKK leader, recently repeated a version of the meme’s central lie in a video streamed live to 8,000 people on Facebook.

The meme has likely gone viral because it deals in an old, blood-soaked lie of white supremacists – that black men pose a particular, sexual threat to white women – and because it cites an official government document as its source.

So how did a US Department of Justice report end up the sole citation on a meme circulating on the white supremacist internet?

Fuzzy math.

A 2008 report from the Bureau of Justice Statistics (BJS) really does seem to state that zero black women were raped by white men in the US that year, and imply that 19,293 white women (that's the 16.4% in the chart below) were raped by black men. (The chart below also seems to show that many more white women - about 88,000 - were raped by white men.)

bad statistic

Foto: source Bureau of Justice Statistics

As Cohen notes, there are tiny little asterisks sprinkled all over this table. But you have to scroll all the way to the bottom of the page to figure out what they mean.

bad statistics

Foto: source Bureau of Justice Statistics

You read that right. Just 10 or fewer women made up some of the samples surveyed for this report, and their small number of experiences has been extrapolated to represent tens of thousands of assaults.

Here's what Cohen has to say about this:

I can't believe we're talking about this. The most important bottom line is that the BJS should not report extrapolations to the whole population from samples this small. These population numbers should not be on this table. At best these numbers are estimated with very large standard errors. (Using a standard confident interval calculator, that 16% of White women, based on a sample of 69, yields a confidence interval of +/- 9%.) It's irresponsible, and it's inadvertently (I assume) feeding White supremacist propaganda.

In other words, a sample size this tiny simply cannot be understood to tell us anything about what's going on at the population level. The odds of picking any 10 or fewer women out of a crowd whose experiences have nothing to do with what's typical are far, far too high.

In an email to Business Insider, Lynn Langton, the researcher who oversees victimization statistics for BJS, acknowledged that the methods of the 2008 report no longer meet the Bureau's standards.

"These posts and memes rely on data that is eight years old," she wrote, "because 2008 was the last year that BJS published Criminal Victimization in the US - Statistical Tables. Many of the estimates in the 100+ tables (not limited to Table 42) do not meet our current standards for reporting so we no longer report out this information on an annual basis. "

As Cohen writes in his blog post, there are also a number of reasons why this table would tell a misleading story even if the data-gathering methods were improved.

First of all, the report uses a household sample. That means that at least one demographic is left out entirely: prisoners. A 2011 to 2012 survey of inmates found that about 3,500 women are subjected to "staff sexual misconduct" in jails and prisons every year - with black women 50% more likely to report this than white women.

"So I'm guessing the true number of Black women sexually assaulted by White men is somewhat greater than zero, and that's just in prisons and jails," Cohen writes.

Second, most perpetrators of sexual assault are close to their victims. And a full 27% are current or former partners of their victims.

As Cohen notes, 2% of white women are married to black men, and 5% of black women are married to white men. Because of differences in population sizes, that means there are far more white women married to black men than black women married to white men. That means that even if white men and black men raped their spouses at exactly symmetrical rates, we'd expect more white women to report rapes by black men than black women by white men.

All of which is to say: If you hear that lie parroted around that black men are targeting white women with sexual violence you should know that it's 100% false. And despite the citation, the Bureau of Justice Statistics does not exactly stand by the numbers, which are based on samples far too small to apply to the general population.

In 2017, Langton wrote, the BJS will release a new report, based on firmer data gathered over the last eight years.