From our earliest days, guys are overcome with urges that cause others to raise an eyebrow or shake their heads. As babies and toddlers, we instinctively and mindlessly twiddle our boy parts. When adolescence sets in, we impulsively jump up to smack every door jam we pass under. And when we reach fatherhood, something deep inside us yearns to throw our babies in the air playfully.The paternal urge to toss babies is an outlier, as it runs antithetical to most parenting practices. Babies are securely buckled in car seats at the beginning of each road trip, even those just a couple of blocks in length, to pick up older siblings from school. They are gently cradled like footballs and strapped into chest carriers to keep them safe wherever we move about the house.And yet, so many fathers at some point in time look their baby square in the eye, flash a big grin, employ their best baby babble voice, and gently give their baby a toss before making the catch and then asking some version of “Wasn’t that fun?”The most generous reading of this routine is that it’s related to the paternal longing for rough-and-tumble play that kids grow to love. It’s the precursor to family wrestling matches in the living room and seemingly unending requests for dads to launch their kids across the swimming pool.“When I was looking forward to becoming a dad, one of the things I was most excited about was playing with my kids and making them laugh,” shared Jacob, a father of three young kids who admitted to tossing at least one of his babies without incident. “But babies aren’t interactive at first, and occasionally, I’d give my kid a little toss out of this desire to have a fun connective moment.”I actually don’t think I ever did a baby toss when my wife wasn’t in the room … So yeah, part of it was knowing that my wife would freak out… But the adrenaline rush of the baby toss must inform our understanding of where this urge originates. Alex, whose son just turned 3, remembers the warm wave of excitement that came over him on the couple of occasions he gently tossed his son in the air.“I wasn’t getting wild and crazy with the tosses. But I think so many aspects of life slowed down in the year after my son was born that the toss felt like a needed quick hit of stimulus,” he says.There’s also an ornery side to the baby toss for many dads. They know it will garner a reaction from others — especially partners and spouses — making the practice a bid for connection. But, and this is the age-old question when dads attempt to deploy humor, is something truly funny if you’re the only one laughing?“I actually don’t think I ever did a baby toss when my wife wasn’t in the room,” Alex recalls. “So yeah, part of it was knowing that my wife would freak out a little bit, and we’d have an interaction that, in hindsight, I probably viewed as funnier and much more playful than she did. Having an audience also probably upped the adrenaline factor.”To be clear, the dirty looks, gasps, and even full-on freak-outs from worried parties are justified, especially concerning babies. Not only are guys notorious for overestimating their athletic prowess — in this case, their surehandedness under pressure — but babies are fragile. Perhaps one of the reasons the baby toss feels exciting is because, on a deep instinctual level, we know it’s dangerous.“The younger the child, the more concerned I am,” says Christina Johns, M.D., a pediatric emergency physician and senior medical adviser at PM Pediatric Care. “We are always more worried about any kind of impact because the bones in their skull are more malleable, and the calcium in those bones isn’t as strong.”A baby’s skull can take up to 18 months to fully close and solidify. The soft fontanelle membranes that pulse whenever babies get upset until their skull bones fuse together don’t offer much protection against falls and other mishaps.And even for dads with quick reflexes who can clear the incredibly low bar of ensuring they don’t drop their child on its head, Johns worries about what might happen if a child younger than two is caught awkwardly. Those scenarios can result in spiral fractures if there is any type of twisting action as the baby is caught or the dreaded nursemaid’s elbow, which occurs when a ligament slips out of place and gets caught between two bones in the elbow joint.Babies start smiling reflexively after a week or two, and socially in response to other people smiling at them after two or three months. But that’s not really an I’m having fun type of a smile.That being said, Johns is sympathetic to the fact that dads enjoy physical play with their kids and that an eagerness to do so with babies can come from a healthy and affectionate place.“Speaking just from personal experience, I have found that dads tend to be more physical creatures,” she says. “My advice is to find physical activities you can engage in with your baby while staying low to the ground. It may be less exciting, but it’s an option that can help satiate one parent’s desire for that type of play without the other partner being like, ‘Are you crazy?’ and then both end up in a big ugly fight in my emergency department.”Johns also suggests finding padded surfaces to play on when engaging in any sort of play that has babies up in the air.“There’s the respective spectrum when I worry less about. When dad is lying on a soft bed mattress and holding the baby up, bouncing them gently, or throwing a baby up just a little teeny bit, you feel like that’s a less risky situation. Still, the risk of injury is certainly not eliminated,” she says.And for those fathers who would explain away the seemingly innocent baby toss with the notion that their baby is a tiny thrill-seeker whose smiles indicate approval of their passive role in dad’s fun? Developmental psychology has some counterarguments that may slow your roll, as you’re likely projecting whatever fun you’re having onto your baby.“Babies start smiling reflexively after a week or two, and socially in response to other people smiling at them after two or three months,” Johns says. “But that’s not really an I’m having fun type of a smile. It could be more reflexive as a response to startle or surprise.”Any way you slice it, the paternal urge to toss babies is, at its core, primarily about dads fulfilling an unvoiced personal need that can be met in much safer ways. And the good news is that relatively speaking, you typically don’t have to wait all that long before your kid is developed enough for rowdy play.Just make sure you enjoy calling the shots while it lasts because that preschooler you can go undefeated against in wrestling matches may soon grow big enough to flip the script and take that title belt from you with ease.