Babies Can Swim Instinctively

Placing a very young infant in water reveals a remarkable set of involuntary responses. Instead of panicking, their glottis automatically seals their airway, they hold their breath, and their limbs begin to make coordinated swimming motions. This is known as the mammalian diving reflex, an innate survival mechanism shared with aquatic mammals like seals and dolphins. Simultaneously, their heart rate slows down in what’s called the bradycardic reflex. This powerful combination of actions helps to conserve oxygen and protect the brain and heart while submerged.

Scientists believe this reflex is a fascinating evolutionary holdover, a primitive survival instinct potentially reinforced by the nine months spent developing in the amniotic fluid of the womb. This innate ability is most prominent from birth until about six months of age, after which it gradually fades as babies (Review) develop more voluntary control over their bodies. While this reflex is the basis for many infant swimming programs, which aim to transition the instinct into a learned skill, it's crucial to understand that it does not make a baby drown-proof. Constant supervision in and around water is always essential.