Study challenges long-held assumptions about animal personalities

A study, published in Animal Behaviour, has revealed their behavioral traits fluctuate dramatically over time, challenging previous assumptions about animal individuality.

Animal personality is typically defined as behavior that remains consistent across time and context. However, the findings suggest that commonly used methods for assessing personality in social spiders, for a start, may be flawed.

Rather than demonstrating stable traits, the behavior of Stegodyphus dumicola spiders (social ‘hippie’ spiders) was found to vary wildly over time, likely in response to internal states such as hunger levels and external environmental factors.

Researchers monitored 28 social spider colonies every two weeks over four months, measuring three key behavioral traits: boldness and fleeing responses when perceiving a threat; and prey capture speed in a group setting.

The study found that while individual spiders initially displayed consistent behaviors over short periods, these patterns changed significantly over time. Scientists also discovered an individual spider’s initial behavior did not predict how it would act later in life.

What the researchers say: “Our study raises the question of whether these spiders truly have personalities at all. We found that their behavior fluctuates so much that it’s misleading to classify individuals as having stable personality traits,” the lead author told us. “This challenges past studies that have assumed personality traits remain fixed based on observations conducted over only a few days or behavioral tests repeated only a small number of times.”

Previous research has revealed that social Stegodyphus spiders live in a cooperative, seemingly fair and equal society where individuals work together to hunt and raise young and even sacrifice themselves for the colony offspring. Rather like human hunter-gatherers.

While researchers in the past have speculated that individuals may take on specific roles such as babysitters or foragers, this study suggests that spider roles are far more fluid than previously thought—again like recent research on hunter-gatherer societies. Instead of fixed behavioral types, spiders appear to adjust their behavior dynamically, based on circumstances.

“It’s tempting to assume that these cooperative spiders have defined roles within their societies, just as we see in some other social animals, like ants,” the researchers said. “However, our findings suggest they may instead live in an even more equal society than expected, where individuals participate in tasks as needed rather than being locked into specific behavioral roles.

“This challenges the idea that individual personalities drive evolutionary and ecological outcomes in this species—at least based on using traditional methods to assess personality in spiders.”

These findings have major implications for wider behavioral ecology research. The paper calls on scientists to design more rigorous studies that track behavior over much longer periods, rather than relying on short-term observations to assess animal personality.

It also warns against assuming that social spiders have stable personality traits, as their behavior appears to be highly flexible and context dependent.

“This study really highlights the importance of understanding how behavior changes over the course of an animal’s lifetime,” the lead author explained.

“Our humble ‘hippie’ spiders have demonstrated how categorizing individuals into ‘bold’, ‘shy’ or ‘aggressive’ based on a few observations is not just inaccurate, it may lead to wrong conclusions about evolutionary outcomes.

“So, much like people, you can’t judge a spider on first impressions and they’re not a fan of labels either!”

My take: This may be the most important study to be published so far this year. It’s worth has little to do with hippie spiders, but in its contention that most of what we have assumed about a species and personality traits is wrong.

A long time ago I wrote that I thought that the whole idea of fixed personality traits was mistaken, and that personality was context dependent. This made the whole idea of psychometric testing absurd.

In 2007, Daniel Goleman’s book, Social Intelligence, was published. In it he put forward the idea that the genes that govern personality express themselves differently in accordance with the relationship one has with the person one is interacting with. He called this “co-creating.” This has since been shown to be true.

But this “co-creating” must involve the changing of personality traits to fit the circumstances or the context. Which is what I said way back then.

More research is needed on other species, including homo sapiens. Perhaps then we can finally junk the idea of the five “personality types” and get around to thinking  of humans as a collaborative and constantly changing species—just like those spiders.