I'am going to risk have stones thrown at me here for saying this, but I have to be honest... I do feel that for teenagers (14-17), having a chaperone, or going on group dates is not such a bad thing... It does give young adults a safer environment to get to know the person they are dating as well as helping to prevent teen pregnancy... It's like a safe practise run before they are old enough (legal age) to 'go out alone' on a date that could lead to physical activities....
No stones here. Chaperones for teens is fine. Group dating (haha, I misspelled 'group' as 'grope' Freudian slip but I caught it) is a good idea for younger people. I went on a few group dates trying to get to know girls I liked and realized I didn't want to be alone with them afterall.
But the WT "rules" on chaperones is different than just protecting young people from their hormones.
The Society counsels against dating unless you're planning on marraige. So the argument for chaperones for teens is a moot point. Teens shouldn't be planning on marriage therefore they don't need to date.
The "rules" of chaperoning apply to all dubs that are dating, no matter the age. So if a 27 year old is dating a 24 year old, they are still supposed to act as if they were 16 year olds on a date. If a 50 year old is dating a 47 year old, the same rules apply.
The WT "rules" of chaperoning are very Victorian and out of date. But they're not quaint or traditional as the old Victorian ways are, they're controlling and manipulative. It's another tool the Society uses to control the thoughts and actions of their followers.