Bad genes

Well, if your genes don’t make you a bad driver, maybe they’ll make you a murderer: “Lighter sentence for murderer with ‘bad genes’”

On the basis of the genetic tests, Judge Reinotti docked a further year off the defendant's sentence, arguing that the defendant's genes "would make him particularly aggressive in stressful situations". Giving his verdict, Reinotti said he had found the MAOA evidence particularly compelling.

Hello? If the court is going to accept evidence about genotypes, wouldn’t the logical thing be to lock up people with the bad genes? Or, to put it another way, isn’t this judgment discriminatory against defendants with the “non-aggressive” genotypes?

Steve Jones is quoted in the article making a similar point:

"90% of all murders are committed by people with a Y chromosome  males. Should we always give males a shorter sentence?" says Steve Jones, a geneticist at University College London. "I have low MAOA activity but I don't go around attacking people."

Good for him! The story goes on to note that this defense is increasingly common in the U.S., where it has influenced some sentencing decisions. It also includes some argument about race as a confounding factor – association studies linking MAOA with violent crime come to different results depending on the ancestry group of the subjects.