When a baby is born they already know how to cry. If you inflict pain, their reaction is to cry.
My question is NOT why do they cry because that is obvious: they are uncomfortable, they are cold, they have been squeezed or as my Mom would say: They are crying because this world is evil and they don't want to be here.
To further remove any confusion: I do not care why they cry.
I had no luck finding anything online except this Q&A with this answer:
So your first natural response is to cry, or as you like to think of it, to produce noises from your vocal throat. This is an inbuilt response. As you grow up you notice every time you emit this noise you are given food, attention, and your basic needs are accounted for. This is a learned response.
The interesting bit from the above quote is:
produce noises from your vocal throat.
- Why do humans know crying?
- If it is not crying and you call it noises from vocal throat then why do babies produce those noises instead of noises such as laughter noises? Clearly they know that the crying type noise will get us to provide them comfort but the laughing type will not.
Perhaps when they are in the womb they can feel when the mother cries, it causes discomfort; so maybe they learn it that way through association. But that begs the question: Why don't they learn laughing in the womb as well?
I will downvote answers that try to state why babies cry since I made it clear that is not my question.