There’s a particular kind of trance that takes hold when you gaze into a glowing, flickering campfire—the kind where you don’t even notice that your marshmallow has gone from toasty treat to active volcano to some kind of science experiment gone horribly wrong, all while you were looking right at it.  Fire has mesmerized us for as long as we’ve known how to control it. It warms us, feeds us, and lights our homes. But something else is clearly going on: right alongside premium entertainment and live sports, streaming services like Netflix somehow find room in their lineup for hours of fireplace footage. For humans, anyway, fire is more than just a practicality—it’s closer to a fixation. Dr. Daniel M.T. Fessler, an evolutionary anthropologist at the University of California, Los Angeles, has a theory about why. He maintains that kids who grow up building fires out of necessity actually lose interest in fire once they’ve mastered it. The fascination so many of us carry into adulthood, he argues, might just be unfinished business. “Once people get good at building fire,” Fessler says, “they’re just not as interested in it anymore.” Master it, and the magic disappears Fessler’s original research on this dates back more than two decades, when he and his wife, an anthropologist, spent nearly three years conducting ethnographic research in Southwestern Sumatra, a large Indonesian island west of Java. They lived in a community where most households cooked over a wood fire, and only a few had transitioned to kerosene stoves.  In these communities, Fessler observed, kids were around fire from the time they could walk, and often had more unsupervised free time than most American kids. Six-year-olds scooped embers from the family cooking fire so they could “bake” their mud pies—tiny imitations of the meals they watched the adults cook every day. By age 10, Fessler says, kids in this community had complete mastery of fire, matching that of “any American outdoor guy.” And that was exactly when the fascination began to wane.  Mentawai woman cooking in the kitchen of a traditional house in her village on Siberut island in western Sumatra, Indonesia. Children in these rural communities are often exposed to fire at a young age. Image: Getty Images / Nataliia Milko Fessler sees this as an example of a concept evolutionary psychologists call “prepared learning,” the idea that evolution doesn’t always hardwire us with full instructions for things, but gives us a head start on learning the important stuff fast. In the case of fire, a natural fascination with fire drives the motivation to master it. Once kids master it, it no longer has the same powerful draw. Conversely, kids whose curiosity about fire never finds a useful outlet may end up spending their adult lives staring into the firepit for hours on end.  “The idea,” Fessler says, “is that if you don’t have the right developmental experiences, that motivation doesn’t shut off, because you never have enough input into the system for it to say, ‘Okay, we’ve done our job. We can step back now.’” Not every piece of evidence fits neatly into Fessler’s theory, though. A 2015 study he co-authored tested college students in Anchorage, Alaska, a population with varying levels of fire exposure and mastery, and found something unexpected: People who’d grown up with more fire experience actually reported more enjoyment of it as adults, not less. Fessler is careful not to overstate the case. “It’s possible that, even in our Anchorage sample, participants did not have sufficiently extensive daily experience with fire as a mundane tool during childhood,” he says. “Or, our hypothesis might just be wrong!” More than a spark Fessler’s theory isn’t the only research into the role of fire in the human story. Research led by Christopher Lynn, an anthropologist at the University of Alabama, has explored a related but separate question: Not why we’re drawn to fire, but what it actually does to us once we’re looking at it.  In one study, he tracked blood pressure while volunteers watched fire under different conditions and found a measurable drop, particularly when the fire included its natural crackling sound. The effect grew stronger the longer people watched. Lynn’s research also touches on dissociation—not in the clinical sense, but the same everyday kind of “zoning out” you’d experience getting lost in a good book or a movie. Fire, his research suggests, might trigger a mild version of that state, where attention narrows, and the mind quiets down. The research points to something bigger than personal comfort, too. Evolutionarily, more easygoing people may have had a real advantage around the fire. Calmer group members tend to create less social conflict. They’re more cooperative, more willing to share food, more likely to watch each other’s backs. A fire that helped people relax might have rewarded those who were able to take advantage of that calm, not only in the moment, but in the alliances and solidarity it made possible.  Fessler, for his part, is not surprised by any of this. “It’s not surprising to me that we see these relaxation effects,” he says. “Part of it is probably due to the stimulus properties of fire itself, part of it is the emotional attraction to it, and part of it is clearly cultural.” Related 'That Time When' Stories Why 90% of us are right-handed Why are airplanes so cold? It’s for your health. Beef tea was all the rage in the 1800s Why only humans sleepwalk Why road trips are good for you, according to science Why summer flies by as an adult—but lasted forever when you were 10 Fessler admits he is a bit puzzled that fireplaces continue to be a selling point for modern homes, given their relative inefficiency, cost, and environmental impact. “If you look at real estate listings, what do they describe? The number of bedrooms, the square footage, the number of bathrooms, whether it has a swimming pool and the number of fireplaces,” he says. “Which is completely absurd.” Grown-ups may never shake the urge for a fireplace to stare into, irrational as it may seem. But there might be a smarter way to handle that same curiosity about fire in kids.  Fessler points to fire safety programs in Germany that skip the usual “stay away” warnings American kids grow up hearing. Instead of telling children to avoid fire entirely, the programs teach them how to build and handle it safely. Fessler isn’t sure how the program’s designers arrived at this approach, but says it tracks with everything his research suggests. “Instead of just saying ‘don’t,’” he says, “they’re saying, ‘here’s how you handle fire safely and responsibly.’” In Ask Us Anything, Popular Science answers your most outlandish, mind-burning questions, from the everyday things you’ve always wondered to the bizarre things you never thought to ask. Have something you’ve always wanted to know? Ask us. The post Why humans find fire so mesmerizing appeared first on Popular Science. ...read more read less