The Impact of Heuristics and Bias in Litigation

WDC Journal Edition: Spring 2021
By: Michael D. Aiken, McCoy Leavitt Laskey, LLC

“[P]eople are not accustomed to thinking hard, and are often content to trust a plausible judgment that comes to mind.”[1] As risk managers, we must accurately assess the strength of a case in front of the jury, which requires insight into how they will assess the case. Yet, we know that jurors are not completely rational decision makers, particularly when facing complex issues.

Instead of parsing through complexity, behavioral psychologists like Daniel Kahneman have shown that people will largely rely on heuristics to make their decisions. A heuristic is a mental shortcut that allows people to make decisions quickly and efficiently, as opposed to expending significant intellectual resources. We all use these subconscious coping skills to avoid having to spend endless amounts of time analyzing complex decisions that we face every day. We are most likely to rely upon heuristics when: (1) the problem is ill structured and complex; (2) information is incomplete, ambiguous, and changing; and (3) when the goals are ill defined, shifting or competing.[2]

It should come as no surprise that jurors (and trial judges) often use heuristics when deciding complicated issues presented in trials and motion practice. Although these decision makers are largely unaware of this influence, lawyers can use them to their advantage. And despite the usefulness of heuristics, many lawyers may not be familiar with them because they are not generally part of the legal lexicon. This article identifies some common heuristics involved in litigation, and provides a framework for how they can improve the evaluation, preparation, and outcome of a case.

I.Identifying Common Heuristics Involved in Litigation

The following is a short list of the most well documented heuristics with some basic descriptive information.

a.Affect Heuristic

With affect heuristic, people rely on the way they feel (your affect) toward the case to make their decisions rather than varying cognitive activity. All perception has an affective component, and our first response upon perceiving a new stimulus is often an emotional one. For example, we do not just see “a house,” we see a “charming house,” an “ugly house,” or a “pretentious house.” The constant flow of emotions eventually forms a stock of more lasting common feelings such as anger, disgust, fear, or sadness.

In terms of analyzing the impact of the affect heuristic, consider:

What feelings arise from your case narrative?

What emotions are attached to each witness and item of key evidence?

How can you adjust the emotional impact of the evidence?

How can you use the jury’s emotions to further your case theme?

b.Authority Heuristic

With authority heuristic, people rely on an expert’s specialized knowledge to influence the decision you make. The implicit assumption is that those in positions of authority wield greater wisdom and power, and therefore complying with them will lead to a favorable result. While we do grow more skeptical of authority as adults, we still tend to consider the judgment of certain authority figures, like scientists, doctors, law enforcement officials, and other experts to be more reliable than perhaps they deserve, even on matters that are outside their domain of expertise. The markers of authority are titles, certain clothes, and the use of certain symbols. Of course, perhaps the most authentic important marker are those things combined with the presence and confidence of a true expert.

In terms of analyzing the impact of the authority heuristic, consider:

Is the core dispute about the facts or expert conclusions derived from those facts?

Do you have the right expert for the case?

How can you damage the other parties’ expert authority?

How can you prepare your expert to appear the most authoritative person involved in the case?

c.Liking Heuristic

With liking heuristic, people rely on their positive or negative disposition towards a person or thing to influence a decision. Factors that increase liking are physical attractiveness, similarity (in dress, interests, background, and demographics), compliments, familiarity under pleasant circumstances, and associations.

In terms of analyzing the impact of the liking heuristic, consider:

How likeable are the key parties and witnesses to the jury pool?

How can you increase the likeability of your client?

How can you decrease the likeability of the opposing party?

d.Ideology Heuristic

With ideology heuristic, people make a decision to choose to follow the person perceived as closest to you in ideology on a particular issue or position.

In terms of analyzing the impact of the ideology heuristic, consider:

What is the predominant ideology of the jury compared to you and your client?

How can you match your theme to the jury’s ideology to resonate?

Finding a theme that captures the jury’s “why” and wrapping your case narrative around it. The theme must focus around letting the jurors feel good about deciding an issue in your favor.

e.Single Factor Heuristic

With single factor heuristic, people make a decision based on—you guessed it—which side is more compelling on a single factor. Put another way, faced with a wide variety of options, a person will decide to base their decision on a single factor and ignore other variables.

In terms of analyzing the impact of the single factor heuristic, consider:

If you boil down the case to a single factor, what could it be?

How can you focus the case on a single favorable decision point or action?

f.Availability Heuristic

With availability heuristic, people make a decision based upon how easy it is to bring something to mind. When trying to make a decision, you might quickly remember a number of relevant examples. Since these are more readily available in your memory, you will likely judge these outcomes as being more common or frequently-occurring. Rather than estimating probability, using base rates, people substitute the more accessible attribute of similarity.

In terms of analyzing the impact of the availability heuristic, consider:

Which jurors are likely to have relevant experience to the issues presented?

Can you analogize your facts to something familiar to the jury?

Can you create a metaphor to compare things that are different yet the same in some respect?

g.Representative Heuristic

With representative heuristic, people make a decision by comparing the present situation to the most representative mental prototype. For example, when trying to decide if someone is trustworthy, a person might compare aspects of the individual to other mental examples you hold. A sweet older woman might remind you of your grandmother, so you might immediately assume that she is kind, gentle, and trustworthy. In short, a representative heuristic is like judging a book by its cover.

In terms of analyzing the impact of the representative heuristic, consider:

What stereotypes, prejudices, and other snap characterizations of witnesses are at play?

What is the first impression of interacting with your client and key witnesses compared with the other parties?

How can you adapt your theme to play off the jury’s snap judgment of what happened?

h.Anchoring and Adjustment Heuristic

Anchoring and adjustment heuristic is the foundational decision making heuristic in situations where some estimate of value is needed. Individuals first use an anchor, or some ball park estimate that surfaces initially, and adjusts their estimates until a satisfactory answer is reached. The initial figure may be suggested by the formulation of the problem, or it may be the result of a partial computation. The anchoring heuristic suggests that we favor the first bit of information we learn, and don’t make enough adjustments.

In terms of analyzing the impact of the anchoring and adjustment heuristic, consider:

What are the potential anchor points in your damage case?

How can you “drop anchor” for your damage number first?

How can you frame your initial damage suggestion as being a valid initial reference point?

II.Using Heuristics at Trial

Heuristics are not a perfect science, as their use is dependent on the situational aspect of decision making. The same juror will use different ones at different times. Another bullet point under every general heuristic would be to consider what other heuristics might be triggered along similar lines. There are many more heuristics than presented here, and you could fairly apply the term to any number of mental models, including common worldviews such as the golden rule, but also stereotypes, and prejudices. Each represents a dimension of the decision making apparatus of each juror.

Of course, it is easy to see that the explicit and direct use of heuristic tactics could get you in trouble and result in a mistrial. Heuristics appeal to the jurors’ emotions, passions, prejudices, or sympathies; or ask the jurors to put themselves in the position of any person involved in the case. The court has all types of safeguards to prevent heuristics from carrying the day. Nevertheless, we know that jurors use heuristics to a large degree, so it is worth trying to harmonize your case presentation with these underlying decisional motivators.

Psychological research on confirmation bias further underscores the critical role of heuristics on a juror’s decision-making. One might assume that the strength of evidence is the most critical factor in the persuasiveness of a case. But even if the jury pays attention to your evidence, confirmation bias will cause jurors to search for, interpret, favor, and recall information in a way that confirms or strengthens one's prior personal beliefs or hypotheses.[3] Anything less than the proverbial “smoking gun” will be explained away or seen as actually supporting the juror’s pre-existing position. The jurors’ personal beliefs, grounded in the use of heuristics, is their guiding light to interpreting the case.


In summary, much of the material presented above probably rings true as “common sense” for experienced trial lawyers. As trials become more infrequent, however, that pool of experience is evaporating. By borrowing from psychological research into heuristics, lawyers without hundreds of trials can have a repeatable framework to better evaluate their cases and persuade a jury to adopt their viewpoint at trial.

Author Biography:

Michael D. Aiken is a partner at McCoy Leavitt Laskey, LLC. He obtained a B.A. in psychology from Miami University in 2002, and graduated from Marquette Law in 2006. He works in the areas of insurance defense, complex product and system failures, and contractor negligence. Outside of work, Michael enjoys learning about computer programming, playing racquet sports, and skiing. He lives in Whitefish Bay, WI with his wife Jennifer and three children.

[1] Daniel Kahneman, Maps of Bounded Rationality: Psychology for Behavioral Economics, 93 Am. Econ. Rev. 5, at 1450 (December 2003).

[2] Gary Klein, Sources of Power: How People Make Decisions (Cambridge, MA, MIT Press, 1999).

[3] For a discussion of bias in the context of mediation statements, see James J. Mathie, Mediation Statements: Give Them the Attention They Deserve and Then Give Them to the Right Person, 16 Wis. Civil Trial J. 3, at 41 (Winter 2018), available at