Yes, and actually, the SAT re-centering is a prime reason why I wonder how valid the Flynn effect actually is-- you know, in terms of being a proxy for an ACTUAL increase in the population mean of whatever it is we think we're measuring with IQ testing...
or if it just reflects that the population most likely to seek out those tests tends to reflect greater and greater numbers of parents who are SEEKING a 'gifted' diagnosis, and actively prepping/grooming kids to get it.
Such grooming doesn't necessarily budge the mean, of course, which is what the SAT seems to suggest.
But it is a curious phenomenon. I tend to think that a shift in the sampled populations explains both things very well-- and means that neither thing says much about the population as a whole... merely about the self-selected sample being measured with the instrument.
