In reply to keith-ratcliffe:
There's something in this, but not the full monty of a generalisation. I was taken caving when I was young and my first ever cave trip was classed as Super Severe. I assumed that was what caving was like and carried on at that level until I swopped caves for climbing. Early expectations do have an impact, maybe not as much as who you knock around with though.
People will of course make progress, and I did that too with climbing from early VDiffs, Severes and VS's to some harder things. Also, the rate of progression is faster now as there is greater access and regularity of climbing than when I began in the 60's.
Now the same issue is coming back to bite me - new indoor climbers quickly move past the easy stuff into harder grades, with the result that route-setters around here at least seem to forget the bumbly grades that the ageing like me need to keep going for mileage and movement. Not many route-setters seem to know an easier route when they see one, maybe because they too are climbing well above that standard.
I could maybe offer myself as a Bumbly Grade Evaluator! There's a late career option....
Dave