Herbert Spencer and Sigmund Freud re-examined the biology underlying the relief theory while retaining the notion that laughter alleviates pent-up nervous energy.

Interestingly, Sigmund Freud, the founder of psychoanalysis, proposed in his book ‘Jokes and Their Relation to the Unconscious (1905) that our enjoyment of a joke reveals what is being suppressed in more serious conversations. Jokes, humor, and mirth are processes and techniques analogous to those of dream work and the unconscious. Freud asserts that the success of a joke hinges on the psychic economy, where jokes enable the overcoming of inhibitions.

In his essay on the ‘Physiology of Laughter’ (1911), Herbert Spencer builds on the idea that emotions take on the form of nervous energy that generates muscular motion. When we experience anger or fear, this nervous energy manifests as small aggressive movements, serving as a discharge of accumulated negative energy. Likewise, laughter also releases negative energy, resulting in actions that differ from aggression or fleeing. Crucially, laughter lacks a specific object—it’s primarily a release of nervous energy through the vocal apparatus. If the release continues, it progresses to muscles associated with breathing, with any remaining energy flowing to the arms and legs, culminating in a sigh of relief. Laughter triggers changes in the body that reflexively affect the mind.

A joke amuses us by reshuffling or dispersing our thoughts, causing a corresponding physical shift within our internal organs. We enjoy this stimulation and mind-transposition. Engagement in humor, music, and play provides all this and more.