Based on the comments at the WP to my piece yesterday, I think an explanatory thread is in order.

The study I wrote about was designed to see if medical examiners' manner of death determination can be influenced by cognitive bias.…
This is important because we tend to think of an ME's opinion as grounded in science than, much more so than, say, a tire tread or fiber expert. But determining "manner" of death is typically much more subjective "cause" of death. This, despite ...
... the fact that a manner of death determination is profoundly more consequential. If an ME determines a death was an accident, we have a tragedy. If an ME determines a death was a homicide, there's a very good chance someone is going to prison for a long time. As I point ...
... out in the article, just *being told* that an ME determined a death to be a homicide has persuaded innocent people to plead guilty. This has been especially true in Shaken Baby Syndrome cases.…
In this study, researchers gave 133 medal examiners a fact pattern in which the medical information about a child's death was identical for all participants. But half were given non-medical information commonly associated with child deaths that are homicides -- the child ...
... was black, and the caretaker at the time of death was the mother's boyfriend. The other group was given non-medical information less associated with guilt -- a white child, left in a grandmother's care. These facts were based on the sorts of cases often presented to MEs.
If the purpose of this study was to see if medical examiners are racist, the critics are correct: this would be a poorly designed study. There was no attempt to distinguish between the variables (race of child; age, gender of implied race of caretaker).
But that was *not* the purpose of the study. The purpose of the study was to see if MEs can be influenced by non-medical information commonly associated with abuse, but that should be irrelevant to a scientific analysis.
Race *is* one of those factors, and that matters. But the study wasn't about measuring racism. It was about measuring bias. In fact, the three real-world examples I gave in my thread tweeting out my piece were all white ...

... men accused of murdering their girlfriend's child after dubious forensic testimony.

The study's findings are important. First, it shows manner of death determinations are far more subjective than commonly thought. Often, once an ME says homicide, police and prosecutors ...
... assume guilt, and go about finding corroborating evidence against a caretaker.

Second, the findings also raise questions about data we have on child deaths that are accidental vs. homicides -- including race-based data. The study suggests some of that data may be suspect ...
... because they're based on findings possibly tainted by cognitive bias. And as the study's lead researcher points out in my piece, cognitive bias based on possibly misleading data can be self-reinforcing. If researchers are more likely to assume certain types of people...
... are guilty because that's what the data say, it can lead to misdiagnosed deaths, which then adds to the misleading data.

Many commenters made a point along the lines of, "Of *course* we should be more suspicious of a boyfriend than a grandmother." Perhaps. But that ...
... should not affect an *ME* determination about manner of death. If after analyzing a child's injuries an ME characterizes a manner of death as "undetermined," and based on statistics or a hunch, a prosecutor looks and finds other evidence of abuse, that's one thing. But ME ...
... determinations about manner of death are usually presented to juries as science. And if they are indeed based on science, MEs should largely come to the same conclusion when looking at the same set of medically relevant information. This study showed that introducing ...
... non-medical information resulted in way too much variability in those determinations.

Think of it this way: Let's say we give 100 crime lab analysts a blood sample and ask them to test it for heroin. For half, we tell them the sample came from a black man arrested outside...
... an abandoned building known to be inhabited by junkies. For the other half, we tell them the sample is from an elderly white woman arrested outside a sports bar. We would expect the drug test results for that particular drug to be *identical* ...
(within the margin for error of that particular test) for both sets of analysts. The race, age, gender, and circumstances under which the blood's owner was arrested should be irrelevant. If we *did* find a lot of variability in the results, we'd be pretty alarmed.
And in this hypto too, there are more variables than just race. But we'd certainly be worried that the study at least suggested racial bias in what's supposed to be an objective finding, and we'd want to see more research.

We'd probably also conclude that ...
... there's no good reason to tell an analyst conducting a drug test on a blood sample about the race, age, gender, or circumstances under which the person the blood was taken from was arrested. It's all irrelevant.

The important takeaway from this study is that ...
...manner of death determinations are often subjective and susceptible to cognitive bias, including but not limited to racial bias. To the extent possible, we should shield MEs from non-medical information, and instruct juries that these findings aren't always hard science.


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More from @radleybalko

20 Feb
New from me. This is an important, first-of-its-kind study.…
I currently know of three men sentenced to death b/c a medical examiner determined a child death the defendant said was an accident to be a homicide. All three determinations have since been challenged by multiple other medical examiners.
First is Jeffrey Havard. Convicted b/c of Shaken Baby diagnosis and sexual abuse claims, all since refuted by multiple other MEs. Judge recently ruled SBS is questionable enough to change death sentence but not conviction. Which doesn't make much sense.…
Read 5 tweets
26 Jan
This piece provides receipts for what I agree is regrettable anti-First Amendment sentiment among some elite journalists and academics. (Though I'm not sure it's all that new). But it also undermines its own premise by conflating that with . . .…
. . . non-state pressure on private companies (social media, cable providers, app stores, etc.) to prevent the spread of misinformation. It also does some eye rolling at the very idea that misinformation is something worth worrying about. Which I find baffling.
OANN and Newsmax built their audiences flattering the president with favorable coverage so he'd promote them. Which he did. The outlets' sole purpose was to present the lies of the man who led the most powerful country on earth as truth. I just don't see how private actors ...
Read 7 tweets
29 Dec 20
In the city’s nearly 200 year history, Little Rock’s city council (which is called a board of directors) has never held a no-confidence vote on the city’s police chief. Today, driven by the police union, it will hold one for the black, reformist chief Keith Humphrey.
The head of the police union just stressed the importance of accountability and law enforcement officer being held to the highest standard. So. Ok.
Little Rock blogger Russ Racop just told black opponents of the no-confidence resolution to “Shut the fuck up.” Then told Mayor Frank Scott: “Fuck you, too.”
Read 5 tweets
2 Dec 20
There are many possible reasons violent crime has spiked this year. Record unemployment. Social upheaval from a pandemic. Mistrust of police. Mistrust of government.

The least likely explanation: defunding the police. Because it hasn’t really happened.
A few cities did immediately abolish some specialty units. But among the dozen or so jurisdictions that cut police funding, most cut only a small percentage, and from what I’ve seen, none of the cuts took effect until FY 2021, which began 10/1. The crime surge began much earlier.
Ah, opponents of police reform say. But the protests still could have spurred the surge in violence, either by encouraging anarchy and mayhem, or by angering police and triggering a de-policing Ferguson Effect.”

So let’s look at crime this year in specific cities:
Read 13 tweets
10 Nov 20
So shortly after the 2016 election, I pointed out how odd it was that the Reason homepage was dominated by stories either mocking and ridiculing the left for being fearful of what was to come, or articles about how Trump might actually be good for libertarians.
Now, in 2020, we have one party so upset about the election, they’re openly fomenting a crisis of democracy. Here’s the Reason homepage today. There’s one article about all of that. There’s a hell of a lot more about the threat posed by Joe Biden. And more riciduling the left. Image
I’m picking on Reason. And I’ll add that there are people there who have sufficiently grasped the threat the last four years, despite the general editorial direction of the magazine. But it really underscores the disappointment I’ve had with my fellow libertarians in general ...
Read 13 tweets
9 Nov 20
A few links on the nonsense claim that Benford’s Law proves “irregularities” in the Biden vote tallies.

First, it’s far from clear that Benford’s Law is useful for detecting election fraud:…
Second, even if it were, district level tallies are likely too fragmented for the law to apply. When you aggregate the data into larger geographical groupings, it’s fine:…
Third, the posts you’ve probably seen on this have manipulated the data.

There’s also lots more discussion of the first two points at the link.…
Read 4 tweets

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