The first project is testing whether exposure to high levels of lead during childhood predicts criminal offending 3 decades later. This question comes up because of the lead disaster in Flint Michigan. Postdoc Amber Beckley and I are doing this project in our longitudinal study in Dunedin, New Zealand. NZ turns out to be the perfect place for a rigorous test of the hypothesis that lead increases risk of crime, because NZ in the 1970’s and 1980’s had the highest airborne toxic lead exposure levels in the developed world. NZ was the last developed country to remove lead from gasoline. What is really important for scientific inference is that the lead exposure levels in NZ were not related to social class. Lead levels were tested in our study members when they were 11-year-olds, and high levels were found in children from rich and poor families alike. Typically, contemporary American studies have the problem that lead exposure is always concentrated together with inner city poverty, so it is hard to tell if lead causes crime, any association could be just a spurious artifact of the effect of poverty on offending. But if lead predicts crime in NZ, that will be strong evidence.

 

The second criminology project involves a whole genome polygenic score. The Social Science Genomics Consortium has done a GWAS on hundreds of thousands of people, using educational attainment as the phenotype (instead of a disease phenotype, such as asthma, schizophrenia, or obesity). Every data set that has carried out a GWAS happens to have also recorded the participants’ education level, which makes this possible. The consortium detected a large number of genetic hits. It is possible to simply add up how many of those hits each individual has, to make a “polygenic score” that can statistically predict how far a person will go in education. Why is this interesting to criminologists? You all know that level of education is strongly related to risk of a crime career. So, postdoc Jasmin Wertz and I calculated this polygenic score for participants in our cohort studies, and tested if it predicts crime careers. It does. In two cohorts, born 20 years and 20,000 miles apart, the polygenic score derived on education predicts self-reports of crime and police records too. And as I predicted back in 1993, the polygenic scores are highest for individuals whose crime career follows a life-course persistent pattern. Using twins or adoptees to test for a genetic propensity toward crime is always aggressively criticized for violated assumptions. What’s interesting is that with a count of molecular variants across the whole genome, assumptions don’t come into it, it is what it is. So although effect sizes are modest, polygenic scores confirm that there is some genetic aspect to a propensity to break the law.

 

So, that is the kind of thing I am working on now. I’ve been told it is also customary at events like these to mention one’s academic journey, the personal background story that led to the work. So, I will mention a few features of a career in crime research that make it the best kind of career to have.

 

When I was a PhD student, my advisor was the late Sarnoff Mednick. Sarnoff is well known to criminologists because he directed the Danish adoption study of crime, published in Science in 1981. When I first met Sarnoff, he told me three important things, and they really influenced my career choice. I wanted to share them with the young people here in New Orleans tonight.

 

First, Sarnoff said that being a researcher is a job that gives you the chance to know a new fact first, before anybody else finds out about it. Now, this appealed to me because I am a very competitive person. And if you are at all a competitive person, you know it’s not enough to win, it’s also deeply satisfying to know all the other people are behind you and losing! Discovering a new fact is an ultimately thrilling experience, it happens when you press that key to launch a statistical package and a few seconds later, you see a new fact that nobody else knows yet. Of course most computer runs don’t yield a new discovery, in fact most of mine yield a big error message. But this thrill of discovery can be quite seductive. Once you experience the rewarding feeling, you are hooked. In my career, the most memorable example of this occurred in 2001, when we tested whether genotype on the MAOA gene interacted with the experience of child maltreatment to predict crime outcomes. We had a decent hypothesis, derived mostly from mouse studies, but we really had no reason to expect it to fit the data. Four of us were standing around the computer, trying to look nonchalant, while biting our fingernails. Glory hallelujah, the interaction term was significant! This was a real discovery, totally unknown until the very minute we ran that analysis. Meta-analyses say that the MAOA finding is still hanging on after 15 years. So, one big advantage of a career in criminology research is getting to win by finding new facts (without having to play any tiresome sports).

 

Second, another thing Sarnoff explained to me was that research is a job that provides you with the means to travel and see the world, while somebody else foots the bills. It’s like the Marine Corps, only safer. As a graduate student I certainly did very badly want to see the world, because up until then had never been off the farm in Randolph county, North Carolina. (Which by the way is an interesting place because today it is officially the most heavily armed county in the USA, counted as firearms per square mile. And I still live there.) In any case, I did graduate with a PhD from what Sarnoff’s students call the “Sarnoff A Mednick School of Travelling Well on Other People’s Money.” Adrian Raine is another alum. And I’ve used that degree to carry out research in lots of countries. And here I am with y’all in New Orleans, while the National Institute of Aging is paying for it. If you are considering a career in criminology research, keep this super perk in mind. Broaden your horizons with scientific travel!

 

The last thing Sarnoff Mednick told me about a career in research is that it is great getting to spend your days working with young people. Bright, attractive, energetic young people. Back then I was a bright, attractive, energetic young person, so I didn’t get the appeal. I thought the really big privilege was having a senior criminologist be my mentor. But now, apparently, I have reached the point of being eligible for a lifetime career award in bio-social criminology. The more senior I get, the more bright, attractive, energetic young people seem truly wonderful beings to me. And, the more senior I get, the more I appreciate that these wonderful beings will let me hang around with them.  Being here with you tonight at the annual Biosocial Criminology meeting is a huge privilege.

 

Thank you very much for giving me your award, Terrie Moffitt.