How would culture change if people were born fully grown?

Let's assume this is from the dawn of time, humanity has always been like this. Babies aren't a thing, instead one day a person is just born fully formed. They can walk and talk, and function as an adult. There is an instinct that drives people to go find others when they are born. There is also an instinct that parents have that drives them to try and find their children, but with no real way to know who that is, people just raise whoever shows up. There are no babies, no children, everyone is an adult. <br><br>So how would culture change with this?