To preface this, I'm asking this question for someone else.
My sister's 14 year old son (let's call him Sam) is not too keen on taking or following instructions. Any time my sister instructs him on anything, he will roll his eyes, leave the house, or go into his room. I understand that teenagers are "rebellious" at this stage, and people here even say to not worry about it, but my sister and I are well justified in being concerned. There are times where his inability to follow instructions could lead to serious consequences.
One time I was over at my sister's house and I had to get Sam for dinner. I had to actually go up to his room because, like mentioned above, he won't even follow simple instructions like coming down to eat. While I was in his room, I noticed that he was watching a video of a guy connecting the terminals of car battery with a wrench. I was suspicious that he was going to attempt it, so I told him nicely, but sternly, that he "absolutely should not do that." As I was putting away the dishes, I heard Sam open the garage door. I ran to the garage as fast as I could and I found him holding a wrench in one hand and he was trying to open the hood of my sister's car.
My sister and her husband don't fight, they don't yell at or hit Sam, Sam goes to a good school, has lots of friends, and he gets to choose what he wants to do (most of the time). Despite this, Sam is extremely insubordinate.
I've read a lot comments here who blame the parents for being too restrictive and not giving the child freedom of choice, but my sister actively tries to be the opposite of that.
I've tried explaining to him why what he was attempting was dangerous, but as I mentioned above, he just rolled his eyes at me and went back up to his room. I also tried what other people here have suggested by asking him for his point of view. I asked him "why" he wanted to do that. I also offered to teach him basic circuit analysis if that's why he tried to play with the car battery.
My question is, how can I get someone like Sam to follow instructions?