Rationality

Rationality is the ability to use reason and logic to make decisions and achieve goals. It involves basing beliefs and actions on clear, structured thinking, critical analysis, and systematic evaluation of available evidence. A rational person uses these tools to justify their decisions and behaviors, ensuring they are grounded in well-reasoned arguments and supported by strong evidence.

The Basic Idea

The average adult makes around 35,000 decisions each day.¹ From trivial choices like what to eat for breakfast to more significant choices about finances or relationships, life is one long stream of decisions. Even the act of choosing an opinion is a decision in itself. Many of these daily decisions produce inherently neutral consequences—whether you eat cereal or toast for breakfast won’t alter the course of your life. We make most of these mundane decisions automatically and efficiently without too much deliberate thought. However, some decisions significantly impact our lives, and this is where rationality comes into play.

Rationality, or the ability to respond to reason, involves actively reflecting on the possible consequences of your actions and deciding on a choice that brings you closer to your goals.² This includes reviewing what you already know, deliberately thinking about new information coming in, using this information to modify your existing beliefs, and applying this knowledge to future decisions.

Rationality is an admired and sought-after quality, but it is not always perfect. We don’t always use rational thought in the pursuit of objective truths. Rather, human reasoning is constantly clouded by emotions and personal motivations. We might use rationality simply to win an argument or persuade someone to make a decision that would benefit us, even if it’s not the best decision for everyone.

Even when rationality would lead to better personal outcomes, we still sometimes fail to make rational decisions. For instance, people who fear flying might take a long drive to avoid getting on an airplane, even though flying is much safer than driving.³
Our decisions are strongly influenced by biases, or unconscious mental processes that happen quickly and automatically.² We revert to these processes when our brains are limited by time, data, or computational power, relying on rules of thumb to help us make decisions efficiently. It’s important to note that these deviations from rationality are not always bad. Relying on mental shortcuts can often drive us towards adaptive decisions where full rationality would be impossible. These biases also infuse our decisions with emotion, allowing us to consider empathy, compassion, and the perspectives and values of other people—ensuring our decisions are not so rational that they are robotic and heartless.