At the voir dire stage of a jury trial, the word “bias” gets used a lot. But do we really know what it means? The courts, in practice at least, hew to a simple meaning: If a potential juror admits to bias, that means they know they can’t be fair to both parties, and can’t promise to render a verdict based on the facts and the evidence alone. In psychology, the term has another meaning, and one with a lot more nuance to it: A bias is really any factor that predisposes someone in a certain direction, with or without that person’s knowledge or control. In these academic circles, there is some controversy on what the true source and function of these biases are, and it is a controversy that has implications for those working more practically in the courts.

A recent study (Castrellon et al., 2021) takes a very innovative approach to try to resolve the question of the source of a common courtroom bias: Are these predispositions emotional reactions, moral judgments, or social tools? A 13-member research team consisting of members from Duke University, the University of Colorado Boulder, the University of Pennsylvania, as well as the consultant David Ball (of “Reptile” fame), set up the study to avoid asking people about their views, or simply looking at their behavior. Instead, they aimed to actually look under the hood at the individual’s mental process. The team applied the science of fMRI to look at activation of the various brain regions associated with different types of thought, they studied what is called the “crime-type bias,” which is the tendency for people to believe that when the crime is more severe, the state’s case is stronger, independent of the evidence. The result they found is that, across a variety of case fact patterns, this bias “does not require emotion or judgment,” but is instead based on social cognition. In this post, I will boil down what that means and what it says to the litigator trying to practically address bias in the courtroom.

What’s a Bias? The Candidates:

There are a few popular accounts for what bias is and where it comes from:

Bias Is an Emotion

This perspective says that bias is an inability to stick to logic, because that logic is overwhelmed by emotion. In that context, bias is an affective animus against a target person, group, or concept. It is disgust, hate, or simply aversion.

Bias Is a Moral Judgment

The second possibility is that bias stems from our own individual or collective understanding of “good” and “evil,” as it applies to a particular concept or person. As a moral judgment, a bias can be thought of as a kind of internalized condemnation.

Bias Is a Social Mechanism

The final perspective is that bias is a tool that individuals apply in integrating their cultural and personal knowledge. It is a “cheat sheet” that we apply in understanding the stories we come across, and in bolstering our own social identity. Who we are is also a product of who we are not, since bias against an out-group helps to prop up our own positive image.

The Winner (At Least in This Study): Bias is Social

The researchers asked 33 participants to undergo functional magnetic resonance imaging (fMRI), to look at brain region activation based on blood-flow, while they read randomly selected crime scenarios that varied the severity of crime (from shoplifting to child sexual abuse) as well as the type and strength of evidence, before rating the strength of the case and recommending punishment.

Looking at the constellations of activated brain regions, they compared them to patterns in a large neuroimaging database to see what forms of thinking tend to correlate with which regions of activation. The result was that, when individuals were applying the crime-type bias, there was no clear correlation with the regions of the brain having to do with intense emotions, nor with the regions having to do with moral thinking. Instead, the neural neighborhoods that lit up were those having to do with how we define and navigate our place within a community: Social cognition. “Our results support a central role for social cognition in juror decision making and suggest that crime-type bias may arise from similar mechanisms that precipitate other biases like stereotypes about culture and race.”

To my thinking, one potential form of social cognition that might be playing a role is motivation. Why would more severe crimes lead us to think that the case against the criminal is stronger? Because the more severe the crime, the greater the motivation to want to believe that the crime has been solved and the right person has been apprehended and punished. That’s the answer that keeps the community safer, so that is the one that we would socially want to gravitate toward. That may be an explanation why those who are in the act of succumbing to a crime-type bias would also be thinking in ways that emphasize social connection.

The Implications

This may seem abstract, but it is really quite important for practical persuaders to think about. It helps to understand why various strategies or appeals might work. For example, I have written before that the Reptile perspective might work, not because there is an autonomous reptile brain lurking in all of us, but because people want to feel like they are helping to protect their community. People don’t reason in isolation, they reason socially, so it helps to keep those social influences in mind as you plan your message and prepare your jury selection.

There is a final and very fundamental implication to the finding that bias is a product of social cognition: It reminds us why the process used in most courts to screen and clear jurors of bias simply does not work. From the perspective of the person with the bias, that bias isn’t a known cognitive mistake to them. It isn’t a case of over-emotionalism or a conscious moral judgment. Rather, it is just a default social process — it is a method they use and rely on in making sense of the world. That is why, if you ask them whether they have flawed judgment, or call it a “bias,” they will quite often say, “No, I can be fair.” And they’ll mean it, because to them it isn’t an error, it is simply an example of the way they think their way through life in a community. A bias is a handy shortcut for that.

So listen as much as you can and as carefully as you can when potential jurors talk or post about how they see the world.