OT: Why actors in their twenties often play teen roles (video)

I can answer this without watching that video.

First of all, there are no child labor laws with adults and they don't have to deal with parents, more lawyers and congested contracts. No studio wants to have a stage parent always on the set, or some meddling mother throwing fits over every little thing that they don't like about what's happening.

Second of all, you can manipulate a young looking 22 year old into looking like a cliche of a 16 year old. Also, chances are the 20-something actor is more experienced and has a broader acting range to handle heavier material. Real 16 year olds tend to be more physically and emotionally callow, unripe and childish-seeming. Therefore, if a group of teen actors (who're the actual age of the character) answer a casting call, I can image that most would be passed up for noting match the look/tone of what the producers had in mind for that character. I don't want to see some bone skinny 115 lb. babyface actor who is 16, but looks 12, losing his virginity on screen...or trying to sell dialogue that's too worldly coming from their young sounding voice. Then they probably have less professional experience, which means more coaching/direction and takes, which eats up time. So at the end of the day, less work is complete.

It's just all around more convienant to use a 20-something actor for teenage roles than actual teenage actors.

The answer is simple... if they cast kids, it would look ridiculous and be lame as sh*t. Can you imagine a 17 year old Bender? He'd be a snivelling little twerp. I see high schoolers and they look 12.