Loner Study Reveals the Biological Reason Isolation Isn’t Always a Problem
Going it alone might help some species survive.
Most of us have been taught that a preference for being alone is a bit of a red flag, even if research has shown that smart people tend to prefer isolation. But a review published Tuesday in Trends in Ecology and Evolution suggests that, from an evolutionary perspective, we might be underselling lonerism. Social isolation is a powerful force, the authors write, potentially shaping genetics, behavior, and maybe even evolution.
It turns out in some species, individuals that spend a lot of time alone are really living their best lives — and biologically thriving because of it. Study authors Allen J. Moore, Ph.D. of the University of Georgia and Nathan Bailey, Ph.D., of St. Andrews University in Scotland, realized this after conducting a systematic review of previous studies on animals with notable loner populations, like some ants, field crickets, and cane toads.
Their analysis contradicts previous research suggesting that being alone is detrimental to an individual’s biological success. “A common, but not universal, finding is that social isolation negatively affects fitness measures,” the team writes. Their review showed that this isn’t always the case. In some instances, they write, anti-social animals exhibit traits that actually make them more likely to survive — suggesting an evolutionary benefit to loner-like behavior.
The cane toad, an animal, some researchers suggest can benefit evolutionarily from going it alone.
Pulling their hypothesis into focus was a study on the behavior of the cane toad, an invasive species in Western Australia. These toads like to push the boundaries of their habitat, venturing off into the frontiers of their societies, where they become socially isolated. A closer look at the behavior of these frontier toads showed that they actually behaved very differently from their counterparts who preferred society. When they finally did encounter other individuals, they were all really into one another, the authors write: “Toads of both sexes from the newly established population in Western Australia were more likely to approach a social partner and spend time with that individual.”
Bailey and Moore interpreted the results of this study to mean that the lonely frontier conditions triggered a change in the behavior of these toads that “increased the likelihood for mating.” This increase is incredibly adaptive on an evolutionary level: the more you mate, the more likely your species is to survive. Their conclusion isn’t quite what you’d expect given human society’s stereotypes about loners and their sex lives.
Cane toads taken from the frontier were more likely to approach a "stimulus toad" in a lab experiment, something that the toads from social environments didn't do.
Studying biologically successful loners like the cane toad, the researchers write, might lead us to rethink how we view social isolation. Lonerism isn’t just a behavior, they posit; it’s an environment. “[Social] interactions themselves represent a type of environment that can select and shape how individuals behave,” says Bailey. In short, being a loner isn’t just about how you act but also who and what you interact with, and how those interactions shape you. The traditional view of social isolation as a behavior doesn’t offer many opportunities to find value in being alone, but looking at it as a way to change your environment changes that.
And so, viewing social interactions as an environment is about more than just semantics. The environment is a key factor in natural selection, and if social isolation can shape the environment, then it can shape the evolution of a species. “Selection reflects the environment,” Moore explained to Inverse. “For example, if there is global warming, organisms that can survive better in this changed environment will reproduce more.”
In the case of cane toads, the researchers hypothesize that social isolation actually drives the evolution of “social affinity.” In other words, it creates friendlier toads. This process is something Moore calls “social selection” — the idea that social environments too can drive evolution.
“Social isolation does influence social selection,” he says. “We tend to think of ‘average’ or typical social environments and ignore the extremes. [Social isolation] is on the extreme end.”
This paper proposes an entirely new way to think about lonerism from a biological and evolutionary perspective. Going it alone, in some cases, isn’t a bad thing. In fact, for some species, it might help them survive.
