But anyway... One idea is that people might start cutting because it is something that is admired in their peer group... And they might come to realise (unconsciously) that endorphins are released with the pain. So... They may come to use cutting to regulate their negative and / or painful emotional state.

I think the pathological aspect comes with the reasons why people do it. If people think they do it because it is respected in their peer group then that doesn't seem particularly maladaptive to me. Of course one might worry about their peer-group on independent grounds, but I don't see anything intrinsically pathological about tattooing or getting ones tongue split or burning 'smileys' into ones arm or cutting....

When the person is having intensely negative / painful emotions and it using it to help regulate those states. Well.. We would like to help them not feel so badly anymore to be sure.