Thanks Spooky - that helps.

Rob - I agree in principle. The actual physical influences of the various planets are quite small, varying as the cube root of their gravitation, but repetition and harmonic resonances make sense as a means of coupling to what we do here.  Thus we have a subtle influence that is often hard to track, and which has thus far defied experimental testing. 

But that is a far cry from what people usually think of when they think of reading their horoscopes in the daily news, and assume that their natures are determined. I suspect that the published accounts of what we "should" experience are more influence than the surrounding planets.

One way to approach this might be to look at a culture in which there are few or no newspapers.  We then would make two hypotheses. First, we propose that birth date will lead to clustering of some kind, based on the attitude of the actors in the cohort, and regardless of what "classical astrologers" might tell us.  Second, we hypothecate that this clustering will differ from pure chance by a significant amount.  Our null hypothesis would then be that no difference exists.  Then we could do a longitudinal study of a few hundred people for a few years (that kind of program provides job security for graduate students in the real world), and then have a look. If we find a difference that implies significant clustering, the next step might be a factor analysis to try to isolate what the differences actually are.

If you get into this, I'd be interested in what you discover.

dave