Smiles Signal

Many who complain about my signaling stories seem to think human behavior falls into neat and distinct categories, including: things we like, and things we do to show off. So if they introspect and see that they genuinely like to do something, they conclude that it cannot be signaling. But consider the simple smile – while we do genuinely like to smile, our tendency to smile depends on socially context in ways that also help smiles to serve as signals:

The zygomatic major [muscle], which resides in the cheek, tugs the lips upward, and the orbicularis oculi, which encircles the eye socket, squeezes the outside corners into the shape of a crow’s foot. The entire event is short — typically lasting from two-thirds of a second to four seconds. … Other muscles can simulate a smile, but only [this] peculiar tango … produces a genuine expression of positive emotion. … Most [psychologists] consider it the sole indicator of true enjoyment. …

College yearbook … Women who displayed [genuine] expressions of positive emotion in their 21-year-old photo had greater levels of general well-being and marital satisfaction at age 52. … Smiles of professional baseball players captured in a 1952 yearbook, … could explain 35 percent of the variability in [their] survival. … Compared to smiles taped during honest interviews, the nurses gave fewer genuine … smiles when lying. … Women smile more than men. …

A massive meta-analysis … from 162 studies and more than 100,000 participants … isolated three variables that influence sex-smiling disparities. … [1:] When people know they’re being watched … sex differences in smiling are greater. … [2:] When men and women share a task or role that follows rigid social rules — like those requiring flight attendants to smile and funeral directors to remain somber — the grin gap diminishes. … [3:] Embarrassing or socially tense situations cause females to smile more than males, but happy or sad situations have no such effect. …

[Researchers] observed the smiles of test participants told to share some of the fee they received from the study with a friend. When people were engaged in this sharing activity they exhibited more [genuine] smiles than during a neutral scenario. … Some were primed for exclusion through an essay task that required them to write about a time they were rejected. … Excluded participants showed an enhanced ability to distinguish [genuine] smiles from false ones … [and] a greater preference to work with individuals displaying genuine … smiles. (more)

Also consider one more data point: our happiest moments by far are during sexual orgasm, but we rarely (NSFW source) smile at such moments.

Signals can be socially wasteful, as some of each person’s gain from their signaling effort can come at the expense of others made to look worse by comparison. Yes our enjoying things makes their efforts less costly, but even so there are real costs that can be socially wasteful.

Even with smiling. For example, we tend to be happier when we smile, and we smile more when we are around others. But I doubt we’d be better off if forced to be around others more often. Our smiles would come at a needlessly higher cost.