Some people claim that 90% of suicides are committed by people who grew up in single-mother homes – the implication being that that kind of upbringing leads to suicide.

I'm not sure one can validly draw that implication. It seems to me they're confusing two different things: the probability that, given that someone was raised by a single mother, they will commit suicide, vs the probability that, given that someone has already committed suicide, they were raised by a single mother. It sounds like they think they're claiming the former while actually claiming the latter.

My statistics knowledge was better in college but I suspect that, if one wanted to validly draw the implication I mentioned, one should instead ask: of all people raised by single mothers, how many end up committing suicide? And then compare that to: of all other people, how many end up committing suicide?

If the former percentage is greater than the latter, maybe there's something to the implication.

1. Is my reasoning correct so far?
2. Specifically, could the former percentage possibly be lower than the latter if we assume that the original claim (that 90% of suicides are committed by people who grew up in single-mother homes) is true?

Sorry about the nondescript title, I'm not quite sure what to call this question.

You are right to question the implied conclusion, but it has to be done on different grounds.

We know that single mother households are a minority, although in the USA the percentage is unusually high, something like 20% (see this). Hence, it must be that suicides happen at a higher rate in single mother households. Hence, comparing the suicide rates among single mother and the rest of households is not going to help your argument.

What you want to look at is endogeneity, i.e. whether there's another factor that causes (in some sense) both suicides and single mother. For instance, mental disease of a child causes break up in family and higher suicide rate.

It sounds plausible to me that in a society that is tuned for heterosexual households with two parents any deviation from a norm would lead to increased stress on children that may cause higher rate of suicide. Hence, only careful analysis of data would support or refute this hypothesis

• "[S]ingle mother households are a minority, [therefore] suicides [must] happen at a higher rate in single mother households." Why? Isn't it logically possible for no one raised by a single mother to commit suicide? Commented Aug 11, 2023 at 13:49
• @DennisHackethal, logically yes, but we know it's not the case Commented Aug 11, 2023 at 22:02
• also, I never heard of the fact that 90% of suicides are by people who grew up in single mother households. the ratio sounds too high to me. there are other similar ratios though, such as high rate of incarceration or violent crime in a subset of population. similarly often people misapply conditional probabilities to draw wrong conclusions leading to racial profiling, for instance Commented Aug 11, 2023 at 22:27
• Even though we know that the suicide rate among those raised by single mothers is not 0, I still don't see why "it must be that suicides happen at a higher rate in single mother households" just because single-mother households are a minority. I could see suicide rates be the same, higher, lower... Like, explain why they MUST be higher. Commented Aug 12, 2023 at 10:52
• Two asides: 1. "I never heard of the fact" – since you seem to question it, it might be better to call it a claim than a fact. 2. To be clear, my question isn't about whether that claim is true. We can just take it as a given for our purposes. Commented Aug 12, 2023 at 10:53

First, correlation doesn't equal causation, so even if there's a correlation, it doesn't necessarily suggest that being raised by a single mother causes a higher risk of suicide.

If you wanted to explore the predictive power of being raised by a single mother on suicide, then yes I'd suggest you look at suicide rates for people not raised by single mothers.

And yes, it's possible that 1) 90 percent of suicides are committed by people raised by single mothers and 2) the suicide rates for people raised by single mothers are lower than the suicide rates for people not raised by single mothers. This would be true if more than 90 percent of people are raised by single mothers.