Princeton researchers discover how loners and introverts will save society

Loners are not dysfunctional failures of the herd. They save the herd. They are herd heroes.

This is the finding of Princeton researchers who empirically demonstrated that across the animal kingdom, loners—defined as “individuals out of sync with a coordinated majority”—likely serve as evolutionary insurance plans, ensuring species survival. For example, if a pandemic of a coronavirus called, say, COVID-19, hit a species, the introverted shut-ins who stayed alone in their homes until they received vaccines would have a 100% survival rate. Their antisocial tendencies would make them invulnerable to the group threat.

Loners exist across the animal kingdom, such as small herds of mammals that skip group migrations and plants that flower days before or after the rest of the species. They’re everywhere. “Now that we’re starting to look for it, we realize that a whole lot of systems are not perfectly synchronized,” says the study’s coauthor Corina Tarnita, an associate professor of ecology and evolutionary biology at Princeton. Loner humans are widespread. “We call them misfits or geniuses, contrarians or visionaries, very much depending on how the rest of the society feels about their behavior.”

But until now, evolutionary biologists have struggled to determine whether loners are random or part of a survival strategy, because studying unpredictable outliers is difficult. So the researchers identified loner amoebas in a slime mold—the ones that, in times of starvation, fail to coalesce with other amoebae into blobs that eventually attach onto passing insects. They found the loners are likely to survive if food returns, and also likely to survive various amoeba blob misfortunes and ailments. Collective action, after all, carries the risk of collective failure.

They also discovered that the loners are not at all random: The ones that hang back have heritable loner behavior, and that their numbers flatline as the amoeba population grows. This means that individual loners exist as functions of their environment and communication with other amoebae—and they can produce social offspring, depending on conditions. (You know this: Witness the super popular girl whose parents are oddballs.)

The researchers write that loners are “critical to understanding collective and social behaviors” across the animal kingdom. So there you have it. Carry on, loners. You’re winning evolution.