Guys should my bro lift weights?

it might cut off his height if he works out at such a young age.

ya
lifting weights is fine.
it can really help with sports an all. I'v been lifting weights since I was 13. I'm still 13 but 14 in less than a month so for about a year now. And it's better for you than doing some weird diet or anything. Just make sure he's okay not to hyperextend anything or lift too much, that can really hurt you. You should always have a spotter with you when lifting.

If his goal is to simply become stronger. Then yes. Lifting weights is an effective way to gain muscle.

If his goal, however, is to lose body fat, then he can't just lift weights if he wants to see results. While you can spot-build muscle, you can't spot-burn fat. Decreases in body fat can only be achieved by cardio exercises and healthy eating. And these decreases in fat won't be particular to one area. It will be a decrease in overall body fat.

So basically he can (and should) lift weights, but he should also do vigorous exercise and eat well too. Lifting alone won't produce noticeable results.

advise him that he is too young to lift weight but if he insists to continue make sure you supervise and maximise the amount of the weight he carries.

the guy that posted before me is short

and no, make him do push ups and sit ups and run and stuff like that.
if he does start doing push ups by now. when he goes to the gym would
probably be able to lift more than what he would lift if he just sat around and did nothing

I started weight lifting with my dad when I was in the third grade, there are some buff little kids out there, because they wanted to lift weights, at least two buff kids were on Ripply's Believe it or not, there are no health risks to my knowledge, and I am perfectly fine so from experience I would say it's fine to have him weight lift with you, just keep an eye on him spot him and make sure he doesn't do too much or do anything without supervision. As long as he's not trying to lift too much he goes through stretches and warm up and everything, it'll be fine and should make him feel better and start building muscle, however I would say he should also do cardio, otherwise he might just be bulk and get depressed that he doesn't seem to be losing weight, and just gaining muscular bulk.

No, he shouldn't, he still has to wait a couple of years, You can tell him to do cardio, not only will it help with weight loss, but outside squats it's probably the best lower body exercise he could get. Also, the lower body plays a large part in upper body strength so it will help him for later.
As for why he shouldn't, it will stunt his growth. Also I'm not sure cavalier was right about the not healing quick enough because when you're younger, every part of your body heals quicker but if I'm wrong I apologize.

I got into football when I was around ten and they have you do simple stuff like push-ups but nothing crazy. A lot more running around. So I agree with Cavelier that finding a sport he likes might work out better for him in the long run. Plus he'll meet more people and make some friends and learn more from joining a team. It'll keep him interested in continuing it later on when it'll benefit him the most, rather than picking up some weights, and getting bored with working out. I mean, lets admit it, working out is only as much fun as you make it, right.

He is a little young. Although in he is probably in junior high right now, and I know they allow them to lift, at least where I went. I wouldn't let him do anything big. If anything at all, some small dumb bells, not too often. It probably isn't a good idea though.

DO NOT lift weights before you're 15-16. Your muscles are not developed to the point where they can be torn and healed rapidly (what happens when you lift weights). Tell him to take up a sport instead. Basketball and Football are good for gaining muscle.

Too young, if he lifts so early, the weights might stun his growth and make him fatter. If he's overweight, do some running/cardio.