I was 12 when I got my first BB / Pellet gun. I shot and killed a bird with it. I felt horrible. So I guess I'm not a sociopath.
Back on topic: I didn't watch the video, I'm a softy when it comes to animals. Which is odd, as I hunt, but I do it in a humane way. I.E. using the proper weapon for the job. Not shooting a damn squirrel with an air-soft pistol. These kids were old enough to know that what they were doing was wrong but "bloodlust" had them and they ignored it. 14 - 15 is well old enough to know what is right and wrong.
For those interested I hunt Coyotes and groundhogs. Nothing for "sport." I live on a farm and such animals are more than a nuisance as they can kill. Groundhogs killing via the hole they dig which will break legs and coyotes using the obvious methods. Depending on range, either a .410 shotgun or a .223 rifle.