I think the idea of the psych tests was that they might be used as a tool for the prosecution and defense to exclude members from the jury pool. Today, potenti

I think the idea of the psych tests was that they might be used as a tool for the prosecution and defense to exclude members from the jury pool. Today, potential jurors can be asked to fill out surveys with questions like, "Have you ever been the victim of a violent crime?" So, asking "Do you make decisions based on your emotions?" isn't too big of a step. In the US judicial system, N potential jurors are made available to the prosecution and defense, and each side takes a turn excluding a person until the number of jurors required is reached. I think the idea is that those on the ends of the normal distribution (in terms of biases relevant to the trial at hand) will be removed so that the jury is more fair than if N jurors were selected at random.