... we, university students (personal experience), but also, I've heard more seniour people in "intellectual" line of employment were forced in the Fall to go help our collectivized farmers pick up potatoes and do some other harvest-related work. (Kartoshka! ;-) )...
I do not know if, given my current line work, I would enjoy assembling high-tech stuff more than that (and would definitely learn more from it), but, overall, I, personally, did not mind at all, it was an excuse to live outside the control of our parents (for those of us who did not go to school in another city/lived in dorm which was less common than in this country), get as drunk as our farmer hosts, shmooze with girls, etc. ;-) As to actual work -- my buddies and myself self-organized to proclaim that we are going to do actual "hard" work, loading bags of potato on trucks, while the rest do "easy" part, pick and load the bags... Of course it would take much more actual time to fill a bag than to throw it into the truck, the rest we spent hanging out and baking potatoes!
Somehow I think that efficiency necessary to assemble iPhones would preclude those Chinese kids to have any good times though, but do not think that it was/is not common in "Communist" countries.
(And, no, we did not get paid, unless you could a bag of potatos which you might or might not sneak back home at the end).
Paul B.