I watched the livestream on Friday. They showed 2 different households -- one messy and out-of-control, the other well-behaved, for the most part. Both households had the same set of Sims.
Some things I remember from the messy household -- the parents had 3 ways of handling bad behavior -- calm, firm, and strict. So a toddler making a mess could be asked not to, told not to, or yelled at. The teen had a journal, which she kept hidden in her bed. Writing in the journal helped with emotional control (might help with other things, too). But when her younger sister found her journal and snooped in it, that made her mad and they quarreled. The younger sister destroyed the teen's science project. I can't remember what the punishment was.
Over in the "good" household, they showed the child sister setting the table, the rocket being launched (the best rocket comes back to earth in 2 stages and you can launch it again). You can decide how the child works on a project -- sloppily or well or with assistance.
They showed the family bulletin board. Besides setting curfew, you can also have your Sims post notes and the children can add drawings they've done. At the end, they had the teen break curfew and get scolded about it. She was aged up before they quit so we could see what trait she got.
As for traits, each value has a U shape underneath. At the top of either end, there's a dark area, so if your teen is in the green or red in that area, they get the trait. Otherwise, there's no new trait.
This is definitely going to add a lot to family play. I'm thinking about moving to "long" for my Sims' age length.
