Ass-Backwards Through the Gateway

March 11, 2018
Posted by Jay Livingston

Imagine that you’re a US Attorney on the drug beat. Your boss is Jeff Sessions, who has announced that he’s going to vigorously enforce laws against marijuana and use the federal law when state laws are more lax. Maybe you also think that weed is a dangerous drug. You do a little “research” and tweet out your findings.

This brief tweet might serve as an example of how not to do real research. The sample, which excludes people who have not gone to treatment centers, is hardly representative of all users. There’s researcher bias since the guy with the ax to grind is the one asking the questions. The respondents too (the drug counselors) no doubt feel some pressure to give the Sessions-politically-correct answer. They may also be selectively remembering their patients. 

But even without the obvious bias, this tweet makes an error that mars research on less contentious issues. It samples on the dependent variable. The use of heavier drugs (opioids, heroin, meth, etc.) is the dependent variable – the outcome you are trying to predict. Marijuana use is the independent variable – the one you use to make that prediction. Taking your sample from confirmed heroin/opioid addicts gets things backwards. To see if weed makes a difference, you have to compare weed users with those who do not use and then see how many in each group take up more serious drugs.

Here’s an analogy – back pain. Suppose that, thanks to advances in imaging (MRIs and the like) doctors find that many of the people who show up with back pain have spinal abnormalities, especially disk bulges and protrusions. These bugles must be the gateway to back pain. So the doctors start doing more surgeries to correct these bulges. These surgeries often fail to improve things.

The doctors were sampling on the dependent variable (back pain), not on the independent variable (disk bulges). The right way to find out if spinal abnormalities cause back pain is to take MRIs of all people, not just those who show up in the doctor’s office. This is pretty much the way it happene in the real world. Eventually, researchers started doing the research the right way and found that lots of people with spinal abnormalities did not pass through the gateway and on to back pain.

The same problem often plagues explanations that try to reverse-engineer success. Find a bunch of highly effective people, then see what habits they share. Or look at some highly successful people (The Beatles, Bill Gates) and discover that early on in their careers they spent 10,000 hours working on their trade.

US Atty. Stuart’s tweet tells a good story, and it’s persuasive. But like other anecdotal evidence and eyewitness testimony, it is frequently misleading or wrong. The systematic research – many studies over many years – shows little or no gateway effect of marijuana. No wonder US Attorney Stuart chose to ignore that research.*

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* As Mark Kleiman has argued, even when a marijuana user does add harder drugs to his repertoire, the causes may have less to do with the drug itself than with the marketplace. The dealer you go to for your weed probably also carries heavier drugs and would be only too happy to sell them to you.  Legalizing weed so that it’s sold openly by specialty shops rather than by criminals may break that link to other drugs.

This Is Not a Pipe . . .

March 7, 2018
Posted by Jay Livingston

. . .  But what is it? Is there a word for a statement that contradicts the assertion in the statement?  For example, one of Trump’s better lines at the Gridiron Club was this.

My staff was concerned that I couldn’t do self-deprecating humor, and I told them not to worry, nobody does self-deprecating humor better than me. It’s not even close.

Not a new joke, but a good one, especially for Trump.

Calling it self-contradiction does not really convey the delightful irony. Trump contradicts himself all the time, but usually the contradiction is not inherent in the statement itself as it is in this instance.

It’s kinda sorta like apophasis (my favorite rhetorical term), but it’s different. I posted about it last summer (here) with Magritte’s painting and this unwitting example that was going around the Internet.

I still haven’t found le mot juste for it.

School Shooters and Broken Homes

February 28, 2018
Posted by Jay Livingston

Suzanne Venker knows what’s wrong with America’s boys – broken homes.

A few days after the massacre at the  Marjory Stoneman Douglas High School in Parkland, Florida, she wrote at Fox News (here)

Broken homes, or homes without a physically and emotionally present mother and father, are the cause of most of society’s ills. “Unstable homes produce unstable children,” writes Peter Hasson at The Federalist. He adds, “On CNN’s list of the “27 Deadliest Mass Shootings In U.S. History,” seven of those shootings were committed by young males since 2005. Of the seven, only one—Virginia Tech shooter Seung-Hui Cho — was raised by his biological father throughout childhood.”

I’ll get to the data in a minute. But I confess, my personal reaction was something resembling nostalgia. “Broken homes.” Reading that phrase was like turning on the radio and hearing The Mamas and the Papas — so popular back in the sixties, and then . . . What ever did become of them? To see if it was just my selective attention, I checked Google n-grams.

I don’t know why broken homes descended the charts so rapidly. Maybe because of its implicit moral condemnation. Broken things are no good. Either try to repair them or toss them out. Also, it was no longer just the poor who were vulnerable to having the finger of blame pointed at them. More middle-class people were getting divorced and breaking their homes. Or maybe the rising wave of feminism raised consciousness that the phrase blamed women. It was a slightly more subtle way of saying that a woman alone would raise children that were a menace to society.

Conservatives at Fox, The Federalist, and elsewhere were not swept up in this revisionist thinking. For them, broken homes remain the eternal bad guy.

As for those mass shootings, Philip Cohen tweeted this chart of the top ten – the most deadly.

Only Paddock and Huberty grew up in fatherless homes.

But what about the boys like Nikolas Cruz, the ones who are angry or resentful at their schools – the teachers who put them down, the students who bullied or rejected them – and come back armed with guns? It turns out we have some data, though it’s not up-to-date. After the Columbine shooting of 1999, the Secret Service and the Department of Education did an extensive study of school shooters. Their report covered 41 shooters involved in 37 school shootings from December 1974 to May 2000. There was a summary recently in The Conversation (here):

While most attackers – 96 percent – were male, the report found that there “is no accurate or useful ‘profile’ of students who engaged in targeted school violence.” . . . Most came from intact families, were doing well in school and were not loners. [emphasis added]

   
One problem with all these studies is sample size. Mass killing and school shootings are rare events. With Cohen’s sample of 10 or Hasson’s 27 or the Secret Services’s 41, only the widest differences (e.g, between males and females) gives us any ability to generalize. For other comparisons  (e.g., broken vs. unbroken homes), the sample, even in the US, is too small. This is one case where a too-small sample is, on the whole, a good thing. Let’s hope it stays that way.

Trump Gets One Right (Partly)

February 26, 2018
Posted by Jay Livingston

It’s easy to make fun of Trump’s claim to heroism, and Andy Borowitz in the New Yorker does it very well.  Trump, speaking to a group of governors today, was criticizing the deputy who did not enter the Marjory Stoneman school during the shooting. Then Trump went on to say,

You don’t know until you're tested, but I really believe I’d run in there even if I didn’t have a weapon – and I think most of the people in this room would have done that, too, ’cause I know most of you.

This was remarkably similar to what Pam Bondi, the Florida Attorney General, had said on Fox News just a few hours earlier: “When you have a school full of students, and your duty is to protect those students, even if I didn’t have a firearm I would have gone into that scene.” Heroic minds think alike, I guess.

What’s ignored in most of the discussion about Trump’s comment is that he said something that was correct: “You don’t know until you’re tested.”

It’s pointless to argue whether Trump would or would not have charged weaponless into the building to confront the shooter. We don’t know. Neither does Trump.

If we’re asked what we would do, and the hypothetical situation is a familiar one, we can make a pretty good guess. Of course, we’d all like to think that we’ll do the right thing. But we can also look at how we’ve behaved in similar situations in the past, and guess that we’ll do something similar the next time. But when it comes to novel situations, our powers of prediction are just not very good, especially when that situation is stressful. When I show students the Milgram film, I ask if they would continue shocking the victim all the way to the end. Nobody ever raises their hand. Yet we can be fairly sure that about half of them are wrong. They’re not lying – saying something they know to be untrue. Neither is Trump.

The TV show “What Would You Do?” frequently concocts some morally questionable behavior and then focuses its hidden camera on a naive person who happens to be present. A shopper in a store sees a clerk being rude to a Black/overweight/transgender/whatever customer. Someone in a bar overhears two women planning to steal the money of man at the bar. What will the shopper or bargoer do? What would you do?

To the list of episodes we can now add: sounds of shooting coming from inside a school. What would you do?

For all these, the most accurate answer is, “I don’t know.”