To the original question from goggles on target. A picture is worth a thousand words, and it's difficult to describe/explain, Hopefully this makes sense:
The angle of both wingtips in space is the same.
The wingtips climb at the same rate, if they were not, you would be rolling.
The inner wingtip moving slower than the outer - otherwise you would not be turning.
As the inner wingtip is slower, takes longer to move a given distance, so will climb more in that given distance than the outer would in the same distance - it is rising at a steeper angle. So, it's angle to the relative airflow is less.
As to experiencing this - I recently did a skills test (converting my license from another contracting state), and was required to demonstrate a stall and recovery off a climbing turn, so I suspect it may well be an exercise somewhere in your training. You'll most likely sit there in a ridiculous attitude waiting for the stall and wondering how on earth anyone manages to do this accidentally.
@bookworm - I know what you mean, and I'm going to have to experiment, but I'm pretty (very) sure i'm not skidding turns! and to 172 driver, I have to say my experience in the 172 is the opposite, perhaps down to rigging differences and / or perception.
And to spinning - glider spinning is a rather different, and more gentlemanly game - the wing drop you get from a C150 is quite violent I'd agree, however, a spin it is not. Provided you're not too shocked (you will be unless it's something you've seen a bit), it can be stopped very rapidly with standard stall recovery and minimal altitude loss - you just fly the wing out of the stall and the problem goes away; it takes quite a while to turn into a spin proper. If however you should start trying to pick up the wing with aileron, and persist in holding the stick back, they you truly are in trouble, ditto if you happen to wait until you're upside down before doing anything about it. Personally I subscribe to the glider stall recovery of getting the nose down pronto, I don't like this powered idea of keeping a relatively flat attitude and hauling it out with power.