7 days a week is recommended for any age to be hygienic but that's should you could never shower i guess i mean it's your choice but don't do that 6-7 is healthy or "normal"
The fact that the cerebrum is still developing during adolescence explains why teenagers act the way that they do is because their brain cannot yet fully comprehend some of the things that they do.
The prefix is different
One is high and the other is low