The phrase “Correlation does not imply causation” has developed in to a Falsehood, as I discuss here. This is in part because people often use the phrase to argue that a particular correlation has no meaning, which is a false argument. It is, of course, true that a correlation does not in and of itself prove a causal link between two things. And, as pointed out in a few places, but I’ll refer you to this Mother Jones piece for background, the relationship between single mothers and homicide and other crime is … well … interesting.
The idea is to blame single mothers for crime. They, being single mothers, would do a lousy job of raising their offspring, who would then grow up and be criminals. There is a racist undertone to this, with a twist: There are those who would like to blame non-white people for all the crime, and this is a version of that; the same racist “science” that underscores the link between melanin in one’s skin and criminal behavior also purports that there is a link between melanin in one’s skin and all the things that lead to single mother hood, from promiscuity to a tendency to not follow social rules to, amazingly, a shorter gestation period which would, I assume, allow single mothers to produce more offspring than might otherwise be possible.
Anyway, there are those who remember the link being made, and here is what the data for violent crime in the US looked like at the time:
Nice relationship there. All else being equal one would want to look at these two variables and see if there is anything to the argument. We KNOW the two variables are related, because otherwise, why would anyone put them on the same graph!@!?? And, once they are on that graph they are perfectly correlated. One small thing that would need to work out is the fact that the criminals are probably not infants, but I’m sure that the time lag thing is just a detail.
Anyway, now, time has passed since that correlation seemed to be explanatory of high crime rates. Has anything changed since then? Let’s look at the data, updated:
Well, now that we see the whole data set, one might wonder why single motherhood rate was not correlated to crime rate prior to 1970. Maybe that’s the time lag thing. It turns out, in fact, that of the 50 years shown on this graph, the correlation seems to work for only about half the time.
Single mothers, you are off the hook. FOR NOW!