Progress Open Thread: March 2021

So despite the fact that I spent quite a while thinking about adopting vs. having biological children a few years ago and came out in favour of having biological children for now based on similar concerns you (and Dale) raise about more adverse outcomes in adopted children, I find your conclusion to strongly dissuade from adopting very surprising.

You thinking that adopting might likely be a life-destroying mistake does not seem to line up with the adoption satisfaction data Aaron linked. Maybe you meant this specifically for adopting teenagers? It was not clear from your comment.

In many ways, I prefer more awareness about difficulties in adopting over the naive 'why don't you just adopt?!' do-gooders who want to have children often hear. So I am grateful that this topic is brought up, I would just prefer a more clear pointing out of trade-offs, as well as more emotional sensitivity on the topic.

When I looked into this, I looked more at qualitative accounts (and also tried to answer a slightly different question - does demand from potential parents for low-risk adopted children outstrip how many such children there are?) and less at quantitative data. While this seems like a clear oversight in retrospect, apparently this led me to a more negative impression than is warranted now looking at the data you linked. If you had told me that 1,5% of biological children have substantial drug abuse problems as defined in the paper and asked me to guess the percentage for adopted children, I would have guessed way more than 3,5%. I was also surprised by the adoption satisfaction data Aaron linked. So if anything, you are leaving me with a more positive impression of adoption, and are motivating me to look into the topic again.

Thus I am surprised you are so confident in your position you would be willing to spend so much time on dissuading people to adopt. (You are welcome to try to dissuade me that this is even worth my time looking into it!) To me, the outcomes do not seem to be 'very predictably bad'.

While on average adopted children have worse outcomes than biological children, this really does not need to be true for each individual making this choice. It is also not the only factor which matters. To name some examples which can tilt the decision: infertility, same-sex couples, previous difficult pregnancies or birth trauma, family history of genetic diseases like Huntington's, more garden-variety heritable risk factors for issues like ADHD, autism and depression, how high risk the potential adoptive children actually are, e.g. based on their age and previous history, etc.

(Arguably nitpicking, in the sense that I suspect this would not change the bottom line, posted because the use of stats here raised my eyebrows)

For some calibration, risk of drug abuse, which is a reasonable baseline for other types of violent behavior as well, is about 2-3x in adopted children. This is not conditioning on it being a teenager adoption, which I expect would likely increase the ratio to more something like 3-4x, given the additional negative selection effects. 

Sibling abuse rates are something like 20% (or 80% depending on your definition). And is the most frequent form of household abuse. This means by adopting a child you are adding something like an additional 60% chance of your other child going through at least some level of abuse

For the benefit of those who didn't click through the link, the rate on their chosen measure is very roughly 3.5% for adoptees versus roughly 1.5% for the general population, which I assume is where the 2-3x came from. I also buy that by adopting a teenager this number is going to be pushed up towards the foster child outcomes (~8%); a guess like 5% ("3-4x") seems reasonable.  

But you can't directly extrapolate from the ratio on a rare outcome to a typical outcome, e.g. a 20% -> 67% (67 = 20 * 5 / 1.5)  change in the absolute likelihood of sibling abuse, which I think is basically what you are doing here, though do correct me if I'm wrong since there were some numbers you gave I couldn't follow. The statistical intuition going into that is rough, but here's a concrete, if technical, example: 

A 1.5% bad tail outcome in a normal distribution means you are 2.17 standard deviations below the mean, a 5% tail outcome means you are 1.64 SDs below the mean, and so you would go 1.5% -> 5% just by dropping the mean by 0.53 SDs. But this would only move a 20% likelihood outcome to 38%, well short of 67% or even your 60%. To get a 20% outcome to 60% you need a 1.1 SD move, which would be equivalent to a 1.5% outcome becoming 14%. The choice of normal distribution in the above is arbitrary, but I expect the pattern to hold among reasonable choices for this case. 

In less technical language: you don't have to move a distribution very much to change the probability of tail outcomes by a lot, whereas almost by definition you do have to move a distribution a lot to change the probability of typical outcomes by a lot. 

Strongly upvoted. This comment provides solid evidence in support of its argument, and led me to substantially raise my estimate of the physical risks involved in adoption. (Edit: This holds even in light of AGB's reply; as he points out, the numbers on risk are still quite high even if you make an adjustment of the type he recommends.)

I also appreciate Habryka's willingness to speak out in favor of a comment that was heavily downvoted and moderated, just as I appreciated Dale's good intentions in his initial comment.

I found Habryka's supporting evidence to be more relevant than Dale's, and his argument clearer — such that it meets the standards of rigor I was hoping for given the topic at hand.

*****

My biggest update here is on the rate of sibling abuse, which I hadn't realized was nearly as high as it seems to be. From page 25 of this report:

The report's definition of "severe assault" (ignore the bit about parents, it seems like sibling violence was measured in the same way):

I'll note that this still leaves room for interpretation. Both of my siblings hit me with objects when I was growing up, leaving marks or bruises in some cases, but I'm still glad they were born, and we get along well as adults. (We also got along well as children, most of the time.)

I'd be really interested to see data like this broken down by the type/severity of violence. I'd guess that a substantial portion of that "37 percent" number comes from things most people would perceive as normal (e.g. a 7-year-old punches her 8-year-old brother in the arm, a 10-year-old hits his twin brother with a Wiffle bat). But I could be wrong, and even much smaller numbers for "truly severe" incidents could mean a lot more risk than I'd expected.

*****

Despite this update, "never adopt" still feels extreme to me, given the chance of a very positive outcome (a child has a loving family who helps to support them, rather than no family) and the high satisfaction rates of adoptive parents (keeping in mind that those numbers are likely to be skewed by a bias towards reporting satisfaction). 

Some factors which seem like they could, in tandem, sharply reduce the risk Habryka identifies:

• Adopting a child younger than your current children
• Adopting a girl rather than a boy (the above report found that boys were more likely than girls to commit violent acts, but I don't know how big the difference is)
• Doing everything you can to learn whether a child has a history of violent behavior (if a 15-year-old has a totally clean record, that seems like useful evidence)

But I'm not confident about the impact of any of these.