The Lazy Brain

Thinking takes effort, and we often look for ways to reduce it.

Psychologists have a word for the efficiency mechanism in how we think: heuristics. When we’re thinking of making a decision, large or small, we use shortcuts developed from our long experience in the world; in chess terms, we do not consider 10 million different moves, but instead rapidly choose the two or three that are most likely to work.

Decisions carry a “cognitive load,” meaning they require brain power. Taking the time to analyze 10 million moves requires significant effort, which uses significant energy. We cannot possibly stop in our day to do the work required to make the most optimal decision in all cases.

Heuristics are shortcuts and thus require us to expend less energy. The results may not always be the best that could have been (they usually aren’t), but they are often good enough for whatever situation we are in. In a process known as “satisficing,” we’ll often search for the first thing in our brain that satisfies our minimum acceptable conditions. This saves time and energy, but it doesn’t mean we get the best outcome.

Some heuristics develop based on previous experience. These are going to be the most reliable if the prior experiences are themselves fairly consistent. Heuristics are more likely to be accurate in situations with a stable environment, frequent exposure (large sample size), and immediate, unambiguous feedback.

In his studies of firefighters, for example, Gary Klein demonstrates the accuracy of the quick decisions that firefighters make in the course of their jobs, and how this accuracy increases over time.2 Why? Fires are governed by rules of chemistry and physics, and thus exhibit consistent behaviors. The more you interact with fires the more you will build knowledge that allows you to intuitively make good decisions in future fire situations.

The more unreliable the previous experience, such as by being too complex to identify true cause and effect or being based on too small a sample size, the more likely your heuristics aren’t going to be particularly useful. Clinical therapy has this problem. The nature of the situation makes it hard to receive immediate feedback on if the therapy is actually working. There could be a host of other factors that contribute to eventual improvement, even simple regression to the mean. The confidential nature and often long duration of the therapy process makes it very hard for each individual practitioner to build experience over a large sample size.

Other heuristics seem to be built into how our brains operate. The most famous of these—anchoring, availability, and representativeness—were extensively studied by Daniel Kahneman and Amos Tversky. Their experiments showed systematic patterns in how people use these shortcuts, including predictable errors.

In Thinking Fast and Slow, Kahneman also writes of the affect heuristic “in which people make judgments and decisions by consulting their emotions: Do I like it? Do I hate it? How strongly do I feel about it?” Kahneman explains that “the affect heuristic is an instance of substitution, in which the answer to an easy question (How do I feel about it?) serves as an answer to a much harder question (What do I think about it?).”3 Answering the easier question is not necessarily a bad thing. We cannot carefully analyze every interaction, and an emotional response can guide a quick choice. Often this is useful, as it lets us put minimal effort into decisions of little consequence, such as buying laundry detergent based on your love of its smell. Sometimes, however, we would increase our skills and knowledge if we put the effort into answering the harder question of what we think about something and not relying on the emotional shortcut.

Heuristics exist because they are way more efficient—efficient in terms of energy use, not necessarily efficient in getting the most useful answer. As Kahneman explains, “A general ‘law of least effort’ applies to cognitive as well as physical exertion. The law asserts that if there are several ways of achieving the same goal, people will eventually gravitate to the least demanding course of action. In the economy of action, effort is a cost, and the acquisition of skill is driven by the balance of benefits and costs. Laziness is built deep into our nature.”4

The good news is, when we are willing to expend the energy, Kahneman offers a couple of corrections for the tendencies of heuristics: remember the base rates and pay attention to the quality of information.5 Suppose that, in the relevant population, 20% of people prefer chocolate ice cream and 80% prefer vanilla. Without information about your new friend, vanilla is the better guess. Even after you are exposed to a series of news stories about a current trend of athletes to partake in cocoa-avocado ice cream, you can still safely guess your friend’s preference of vanilla. Always go back to the base rates and then ask if this new information you have could affect those rates substantially enough for you to change your guess. Without this vigilance, the availability of the news stories or the anchor of the word cocoa would likely prompt you to choose chocolate when asked to guess your friend’s favorite ice cream. The news stories alone need not tell you anything about your friend’s preference. Relevant information about the friend could change your estimate; otherwise, the base rates are the starting point.