When Not to Trust Your Gut: Cognitive Bias in Legal Decision-Making

Attorneys at all levels of experience are called upon to make judgments. Whether it’s strategically conceding a point at oral argument to burnish your credibility with the judge, or determining how much detail or background a senior partner wants in a briefing, excellent lawyers are prized for their decision-making abilities. We tend to trust our gut in many of the daily aspects of practice that require making sound decisions, especially as we leave the first few years of practice behind and begin to feel more experienced.


But what if our gut gets it wrong? Lawyers looking to hone their skills need to do more than think about their cases; they need to think about how they think about their cases. Increased vigilance is necessary to prevent cognitive biases from infecting your logic and introducing errors into your thinking. Let’s examine some of the most common cognitive biases in legal thinking, as well as strategies for neutralizing them. Thwarting cognitive biases will help develop the decision-making skills all attorneys need to succeed.

One of the most common types of cognitive bias is the availability heuristic. Heuristics are mental shortcuts that we employ constantly while navigating our daily lives. Their upside is that they yield a quick mental result without much effort. Their downside is that they can facilitate the introduction of logical errors into our thinking through a cognitive bias.

The availability heuristic is simple: When judging the likelihood that an event will occur, our judgment is strongly affected by how easily we are able to recall other similar instances. The availability heuristic operates through the mental substitution of an easier question in place of a harder question. When asked to estimate the frequency of an event (which is hard to do), we will often instead report an impression of the ease with which examples come to mind (which is much easier).

I defend employers, and I am often asked to advise companies on the likelihood that a former employee will file suit. Given how easily I can recall numerous instances of protracted litigation and memorable jury trials in employment cases, it requires overcoming the availability heuristic to remember that in most instances, former employees do not sue their former employers. A former employee not filing suit is orders of magnitude more likely, but those are not the cases that spring to mind when the question is asked. A skilled client advisor has to put in the extra mental effort to avoid the availability heuristic when answering a client’s questions, and base answers and advice not just on the fluency with which additional instances can be recalled, but also on information that is more difficult to retrieve. An honest assessment requires answering the difficult questions instead of substituting an easily supplied impression.

Another cognitive bias common in the legal field also relies on substitution: the affect heuristic. The affect heuristic inserts feelings of like or dislike into decisions and judgments, displacing reasoned deliberation and giving conclusions primacy over analysis. Far less mental work is required to determine how we feel about someone than to determine the objective strength of an argument or claim.  Errors in logic will inevitably result from reliance on the affect heuristic. The affect heuristic is doubly devious, in that it also tends to constrain our mental search for information to facts that confirm our existing beliefs.

The affect heuristic comes into play as a case proceeds, and attorneys for both sides increasingly identify with their respective clients, positions and arguments. Simply put, each side will usually like their client better than the opposing party, and each side may develop some negative feelings about opposing counsel. These feelings can easily lead to a dangerous overestimation of your likelihood of success, and a similarly perilous underestimation of your opponent’s arguments or ability to sway a fact-finder.

In countering both the availability and affect heuristics, the key is to slow down your thinking, and impose logic and reasoning into your analyses and deliberations. Start by asking if you are substituting an easier question for a harder one. For example, are you reporting on the fluency with which you can recall other instances of a similar event, or are your conclusions too aligned with your enthusiasm for your own positions or arguments? Substitution is a common element in many heuristics, and guarding against its insinuation into your legal judgment will go a long way towards keeping wayward mental processes at bay.


One of the most effective ways to make sure you are objectively evaluating the case before you is to conduct a thorough premortem. A premortem is a hypothetical exercise in which a postmortem of a disastrous outcome for your case or argument is performed in advance. The procedure is simple. Gather those in your firm or meet with those co-counsel who are knowledgeable about your case, and present the following: “First, let’s briefly describe our plan for this case. Next, imagine that we’re 18 months into the future. The jury/judge/administrative law judge/arbitrator has just handed down a decision, and it was an absolute disaster for our client. Finally, please take the next five minutes to write down how that disaster occurred.”

Conducting a premortem provides many advantages for evaluating a case. First, it counteracts our natural tendency to suppress doubt and misgivings as decision points approach and a group consensus emerges. Second, it frees the imagination of knowledgeable individuals to evaluate a case in a new way—and be able to counteract previously unexplored weaknesses. Premortems may be conducted several times at key points in a case, and may be valuable when deciding whether or not to take on a client, how to best insure the success (or failure) of a motion for summary judgment, or preparing for trial. While the discussion of the case plan may be spoken, each individual silently writing the disastrous outcome’s history is key to ensure you obtain the widest possible variety of responses.

Taking the time to interrogate your mental process and to recall the facts that weigh against your favored conclusions will ensure that your decisions are the product of intentional reasoning and not flawed heuristic shortcuts. Consulting a trusted advisor or mentor can also help provide some crucial objective distance and clarity. Your clients,  your partners, and your gut, will appreciate the accurate and trustworthy advice that results.

 About the Author

Damien T. Munsinger is an attorney at Barran Liebman LLP, where he represents employers in discrimination, wrongful termination and a wide variety of other employment claims and issues. Contact him at 503-276-2112 or dmunsinger@barran.com.

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