Briefly Noted: The Myth of Rationality

Most people accept that emotion influences judgment and shapes interpretation, but what’s less well known is that the last few decades of affective neuroscience have established that emotion is the foundation of reasoning itself.*

This is a strange idea if we think of ourselves as primarily rational, but the fact is that no one is primarily rational. That’s because reasoning emerges from systems that were never designed to produce objectivity in the first place. To understand why, we have to look briefly at how the brain constructs emotion.

At every moment, our brain is predicting what will happen next and regulating our body in preparation for those eventualities. It adjusts our heart rate, breathing, hormone levels, energy use, and a host of other physiological processes, producing a continuous stream of interoceptions: sensations we perceive inside the body. The collection of interoceptions present in any moment gives rise to our most basic sense of feeling good, bad, or neutral. This is called affect. Emotion emerges when this affective experience meets our conceptual understanding of a situation, and together they create our conscious experience of what’s happening.

Our impression of rationality emerges downstream from this process. By the time we begin thinking deliberately about something, our perceptions have already been shaped by emotion. What follows feels like neutral analysis, but it is operating within a conceptual space that emotion has already defined.

For example, when our brain produces anxiety, the world appears threatening, and we reason in a conceptual space where neutral or even positive events carry a sense of risk. When it produces depression, the world appears bleak and pointless, and our reasoning proceeds within that frame. In each case, we do not reason our way into these conclusions. We reason within them. Emotion defines the conceptual space, and our rational mind operates within it.

This is why rationality feels objective from the inside. Our experiences present themselves as simple observations, not as predictions constructed by the brain. They do not feel shaped by emotion. They feel discovered.

Rationality, as we usually imagine it—a detached, emotion-free view of objective reality—is largely a myth. We are all feeling machines that think, and we routinely experience those subjective feelings as objective reality.

*Barrett, L. F. (2017). The theory of constructed emotion: An active inference account of interoception and categorization. Current Opinion in Psychology, 17, 1–7.

*Damasio, A. R. (1994). Descartes’ Error: Emotion, reason, and the human brain. New York, NY: Putnam.