Why Do Humans Get Hiccups? Hint: It’s An Evolutionary Reflex From Our Fishy Past

InnovationScienceWhy Do Humans Get Hiccups? Hint: It’s An Evolutionary Reflex From Our Fishy PastByScott Travers,Contributor.Forbes contributors publish independent expert analyses and insights. I write about biodiversity and the hidden quirks of the natural world.Follow AuthorApr 22, 2026, 08:30am EDT--:-- / --:--This voice experience is generated by AI. Learn more.This voice experience is generated by AI. Learn more.The hiccups you’ve been cursing since lunch are older than you could ever possibly imagine — a ghost signal from ancestors who never set foot on land.gettyThere is something incredibly humbling about a hiccup. It arrives uninvited, refuses to be reasoned with and departs on its own schedule. Yet for a phenomenon so trivial, hiccups have attracted a surprising amount of serious scientific attention. And the more researchers have dug into what is actually happening when we hiccup, the stranger and more ancient the answer becomes.The short version is that when you hiccup, you are, in some sense, briefly reenacting the breathing pattern of a tadpole. The longer version requires a detour through 375 million years of vertebrate evolution — and it’s considerably more interesting.What Are The Hiccups?Medically, a hiccup is called a singultus, directly translated from Latin to “sobbing.” Mechanically speaking, it’s an involuntary spasm of the diaphragm that fires in concert with the intercostal muscles of the chest. Almost simultaneously, within about 35 milliseconds, the glottis (the opening between the vocal cords) snaps shut. That abrupt closure is the source of the characteristic sound. The “hic” is not the breath itself, but the sound of a door slamming.The entire sequence is orchestrated not by any higher cognitive region of the brain but by the brainstem, one of its most ancient structures. This is a reflex, in the truest sense, so it bypasses conscious control entirely. You cannot decide not to hiccup, any more than you can decide not to blink when some...