It’s a fascinating fact that newborn babies have an innate ability to swim, a skill known as the “swimming reflex.” While most infants lose this ability within a few months after birth, it suggests that humans might carry remnants of an evolutionary adaptation tied to aquatic environments. Let’s explore this natural phenomenon, why babies are born with it, and what it tells us about our evolutionary past.

What Is the Swimming Reflex?

The swimming reflex, also known as the “bradycardic response,” is a set of automatic behaviors exhibited by newborns when placed in water. When submerged, babies naturally hold their breath, move their arms and legs in a coordinated swimming motion, and maintain a slow, steady heart rate. These reflexes are part of a larger group of survival instincts seen in early infancy, including the Moro reflex (startle reflex) and the rooting reflex (which helps them find the breast for feeding).

The swimming reflex in newborns is only temporary and usually disappears around 6 months of age, as babies’ brain and motor functions develop further. But for the first few months, this ability is quite remarkable.

Why Do Babies Have This Ability?

The existence of the swimming reflex in infants has sparked much debate. Some scientists believe it could be an evolutionary remnant from when human ancestors lived in or near water. This idea is linked to the Aquatic Ape Hypothesis, which suggests that human evolution was influenced by semi-aquatic environments. Proponents of this theory argue that traits like our ability to hold our breath, control buoyancy, and swim could have been developed during a time when early humans spent significant periods in water to hunt or gather food.

The Bradycardic Response

One key aspect of the swimming reflex is the bradycardic response, a reaction that occurs when a baby’s face is submerged in water. The heart rate slows down, conserving oxygen and allowing the baby to hold its breath for a short time underwater. This response is part of the mammalian diving reflex, which is found in many aquatic mammals such as seals, otters, and dolphins. The diving reflex is present in all humans, but it’s especially strong in infants, further supporting the idea of an ancestral aquatic connection.

Evolutionary Theories

While the Aquatic Ape Hypothesis is still a topic of debate and not widely accepted by all anthropologists, there are other evolutionary theories that can help explain the swimming reflex. Human infants, like the young of many other species, are born with instinctual behaviors that aid in survival. The ability to swim or at least stay afloat might have provided some evolutionary advantage in environments near rivers, lakes, or oceans.

What Happens as Babies Grow?

As babies grow, their swimming reflex disappears, likely because they begin to rely more on conscious control of their muscles and movements. However, this doesn’t mean that the ability to swim is lost entirely—it simply becomes a skill that must be learned or re-learned later in life. Early exposure to water can help reinforce this natural reflex, and many swim instructors encourage parents to introduce their infants to water in a controlled, safe environment to make them comfortable with it.

Conclusion

The innate ability for babies to swim at birth is an intriguing reflection of human evolution and our natural instincts. Whether it’s tied to an ancient aquatic phase in human history or simply an adaptive reflex for survival, this ability demonstrates the complexity of our biological makeup. While babies lose this reflex after a few months, it offers a glimpse into the remarkable skills that humans are born with and how our bodies are finely tuned for survival from the very beginning.