Some school gates are a bit quichey ime.
The ones I pick up from now are fine.
State school: huge cross section of parents in terms of age/sex/wealth/no. of kids, also a fair few nannies/au pair/childminders/grannies, everyone chats away.
Private school: mostly 30 something mums, a few dads/nannies, with the oddd granny and childminder, everyone really friendly, no huddled groups glaring evilly about the place.
I was the only nanny picking up from a playgroup once, and NONE of the mums would speak to me, they used to phone and make playdates with my employer, and thought I was a forelock-tugging dimwit. None of this stopped them dumping their kids on me when it suited, obv.
Can't say I gave a shit, though.