April 19, 2008

Quick debunking: The rape rate

Myth: The rape rate in the US has fallen 25% over the last 25 years.

Example: I found this rather bizarre claim on a YouTube video arguing that, first, the rape rate had fallen, and second, this was because of the increased availability of pornography. Hence, third, YouTube should allow pornography. Not only is this a post hoc ergo propter hoc fallacy, but it didn't even sound true.

Response: Historical statistics on rape are surprisingly hard to find online. 1960-1998 data are here, and 2004 data here. In 1980, the rape rate was about 36 incidents per 100,000 people. In 2004, the rape rate was 32 per 100,000. That's a decrease of about 9%.

Now, in about 1992, the rape rate peaked somewhere around 42 or 43. This makes for a 25% reduction. But focussing on this period of time is completely disingenuous. In the early 1960s, before the lifting of indecency laws allowed the pornography industry to flourish, the rape rate was less than 10 per 100,000. So, since pornography became easily available, the rape rate has seen a net increase of 200%.

This is evidence supporting the claim that pornography encourages, rather than discourages, rape. But it's far from conclusive. There are simply too many other factors that aren't being taken into account to draw that conclusion.


Drew said...

Ok, so when someone on YouTube says that the rape rate has fallen since the widespread available of porn, and assumes causation, that's a fallacy.

But when you say that the rape rate has increased since the widespread availability of porn, that's "evidence" (albeit inconclusive) that pornography encourages rape.

No, it's not evidence of any such thing. At the absolute most, it is suggestive that there may be such a link.

Noumena said...

I'm not assuming causation. I'm not even inductively drawing that conclusion. I'm saying that this is very rough and preliminary evidence for that hypothesis, and that much more data need to be brought into play.