Since antiquity, academics have been trying to make sense of this abstract thing we call “the economy”. Only recently, though, has economics been turned into a type of science – complete with its own esoteric mathematical models and laboratory-like experiments. When these academics did attempt to bring scientific rigor to such a complex field of study, they were forced to make some highly simplified assumptions about the nature of human beings. Central to these assumptions is that all economic actors – the people who decide what groceries to buy and how much to save for retirement, etc. – are completely rational decision makers who take into account all of the relevant information available in order to select the best options.
As it turns out, the field of law makes very similar assumptions, not about economic actors, but about jurors. Legal scholars believe that jurors, when properly screened for personal biases, can make logical and informed decisions with regard to guilt or innocence based on the evidence presented to them at trial. They might be momentarily swayed by a cunning witness here, or a gruesome crime scene photo there, but overall they will be able to stay focused on the big picture and view the evidence in totality when considering whether the state has proven its case beyond a reasonable doubt. Or so the experts tell us.
In fact, the assumptions made by scholars in both fields about human rationality and decision-making could not be further divorced from reality. Human beings are rarely, if ever, perfectly logical, and their choices and decisions can be influenced by the subtlest factors.
Luckily, some economists have started to wake up to this fact. A few brave pioneers have created a new field called “behavioral economics”, a field that acknowledges our innate irrationality and seeks to analyze and understand it rather than sweep it under the rug. In bringing these psychological idiosyncrasies to light, policy makers are starting to grasp how and when peoples’ ability to make proper financial decisions goes awry, as well as how to nudge people to do better.
As far as I know, no such officially recognized academic analogue exists in the field of law. Many judges opine freely on what types of evidence are more likely to be prejudicial than probative to a jury, but these opinions are based on nothing more than a hunch which are subject to the judge’s own errant reasoning. Empirical evidence is completely absent from any discussion about juror psychology, and what little of it does exist is used more as tradecraft for lawyers seeking to manipulate trial verdicts than data for those interested in improving the fact-finding process itself.
The current resistance (almost pathological hostility) from legal scholars and practitioners, like trial judges, towards the notion that cognitive biases from highly irrational individuals can hijack the fact-finding process and destroy the integrity of the sacred jury verdict, is reminiscent of the early hostility from theoretical economists toward the idea that economic entities frequently make suboptimal financial decisions. For the economists, they desperately needed the stringent rationality assumption in order to justify their mathematical models of the economy.
Mathematical equations follow certain logical rules, and so if people in the economy are to be represented by these equations, then they too must follow these rules. Computations have no room for creativity, and so if economists were to utilize their models to calculate things (like GDP, or inflation), neither did the actors in their equations.
In a criminal trial, a verdict is also a sort of computation. Information is fed into the courtroom and, at the end of the process, out comes another piece of information. But instead of a number, it is a binary output: guilty or not guilty. Given that the stakes of the verdict are incredibly high, we want to have confidence in the computation. And this why those who practice the law want so badly to believe that jurors are capable of making decisions based on proper reasoning and sound logic. And given that the jury is the only line of defense preventing the state from snatching away a citizen’s freedom (possibly his life), most people also want to believe that jurors are up to the task of rendering a fair verdict based on a rigorous analysis of all the evidence.
But just as behavioral psychology did with traditional economics, we will find that modern research into the human mind will destroy any justification for the assumption that human beings are careful, deliberate decision-makers. And we will discover that this holds true not just for jurors, but also for the detectives that investigate the crimes, the lab technicians that analyze the forensics, the prosecutors who bring the cases to trial, and the judges who sentence the convicted.
The new discipline of behavioral law will represent the first step in truly understanding how the criminal-justice system actually operates and how to remedy the overwhelming number of systemic and systematic errors that lead to tragic outcomes and force us to question whether the system’s values are compatible with those of Western liberal democracy.