CP Psychologists anyone remember?

Back in dem days 1973 I can remember a strange bunch of men in long macs appearing one afternoon in our mathematics class which was being run by Derek Skinner a pedophile as it turned out.
They were introduced as "conducting a psychological survey".We were to write a few hundred words on all our experiences of stress particulalry our felt reacations to being under CP."as an excercise.Then we were to hand these in to the mysterious men who took them and dissappeared.We never heard anything again.Did anyone else encounter this brigade?Were they part of some strange natinal survey?What happened to the essays?How many other schools did they visit?I alwasy thought there was something a bit funny about the way they emphasised the words "C.P".
Dunno perhaps they were just some chums of Derek?
Another time when me and sum kids was playing by the river a strange bloke yokel local type came up to us and started asking lots of questions 'bout whether we "got the cane at school"...etc.We smelled a rat and scarpered.
He must have been pushin'60.This was around 1972.