What does Parenthood actually change?

Parenthood gives you access to a lot of new traits that help round off a personality. They're reward traits for how you raise a child and they do require some work to get them. It 100% improves the process of raising a child/teen because it has a system built to score whether they have good/bad manners, Empathy, Responsibility, etc. I've noticed the traits from Parenthood are a bit stronger than the base game traits. An Insensitive, argumentative, mean sim will be hell on earth at social interactions. Good Manners will grant you a polite introduction that can start you off as friends with any sim you meet. It's a pretty beefy pack for adding on to gameplay. I try to play most of the pre-built sim teens to get them a fitting a set of childhood traits.

So I like to play Cassandra as the rebel and she usually grows to young adult gaining the Uncontrolled Emotions trait. Sometimes Insensitive too. I add Hot Headed to her main traits. Uncontrolled Emotions means she holds onto excessive feelings longer so she's got presence in most situations. IF she gets tense she tends to get sad or angry in response to it and then she spirals. Sofia Bjergsen tends to end up with Good Manners on top of her regular traits so she's pretty pleasant as an adult.