Why are babies small and grownups big? Why are babies so helpless, instead of little versions of adults? Do babies know they're babies? How do babies grow? How do babies learn to talk?
Kids have been sending us lots of questions about babies! This week weβre learning more about the development of the human brain Β with Celeste Kidd, professor of psychology and primary investigator at theΒ Kidd Lab at the University of California Berkeley.
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It seems like a really bad idea, right? Human babies rely on adult humans for everything, while babies of some species never meet their parents and are able to take care of themselves as soon as their born! Why is that?
While researchers arenβt sure on this one, Celeste Kidd says there are a lot of theories.
βBecause we are very intelligent, we need bigger brains to account for all the things we can do that other animals canβt do. If you have a big brain and youβre born via live birth β meaning you arenβt born from an egg β then thereβs an upper limit on how big your head can be when you go through the birth canal,β she explains.
In other words, we need those big brains to do all the things humans do, but a human head with a fully developed brain canβt fit through the birth canal.
βThe bigger your head needs to be ultimately, the more immature you need to be born,β Celeste says. So we have to develop and grow outside of the womb. Weβre born with some of our brain power, but our brains keep growing long after weβre born, well into our 20s. And there are some advantages to that long period of childhood.
βIf you require dependence on your parents for a really long time, which humans do, that creates a lot of opportunity for you to learn a lot of stuff about your culture and the other people that youβre being raised with. We have a lot of knowledge that is unique to us as a species, and thatβs unique to us as social groups,β Celeste says.