Why are the youths all portrayed as psychopaths?
Out of this entire group there is not one except perhaps the Thomas Turgoose character towards the end who is shown as likeable in any way. Even the female is vile. It shows a couple of them who seem to be having some semblance of a conscience or some human empathy, like a few times the black kid looked like he was about to say enough is enough I can't take it that far but no they all just carry on and don't seem put off enough to leave after cutting up and burning people.
This is extremely unlikely to be the case, surely? That they would ALL be led astray by the one psychopathic kid? It's as if the film implies they are all used to torturing people in this way and they just look a bit shocked because it's gone a little bit further than normal. It seems very unlikely that a whole group of youths/kids would see this stuff as no big deal like the way they did.