Why do newborn boys cry louder? Evolutionary survival mechanisms explained

The researchers think this is because, statistically speaking, slightly more boys than girls die before the first year of life. From an evolutionary point of view, boys would shout a little louder to get more attention and thus have better chances of survival. That is evident from it research published this week in iScience.

According to author and obstetrician Beatrijs Smulders, newborn babies have many reflexes left over from evolution to survive. “When babies are born you see the moro reflex,” she says to Editie NL. This is also called the startle reflex: the baby spreads its hands and arms upwards. “This is elemental from when we were in the monkey stage. It was important to hold on to your mother.”

Survival strategy

And so there are more survival mechanisms. “Crying is a way to get nourishment, and laughing is also a survival strategy. It produces endorphins in the mother, which increases the bond between mother and child. This gives the child loving attention.”

Evolution

Humans evolve to better survive as a species. “Evolution can actually be seen as a very gradual change of species over time,” says biologist Mátyás Bittenbinder of Naturalis and the VU.

Species (and therefore also humans) do everything they can to survive. Babies learn to demand attention from the mother in order to survive. And those reflexes go along with the evolution. “Another good example of evolution in humans is the use of tools,” Bittenbinder continues. “Over time, we’ve become very good at grinding stones, which helped us survive better as humans.”

This also applies to animals, by the way. “Due to small changes in the DNA, the species changes. The peacock with the most beautiful feathers has the best chance of mating, and therefore of reproducing. This ensures that that small change in the DNA is always passed on. This is how male peacocks more and more beautiful.”