[lepton]

I’ve seen that chart, so I knew what you were referring to.

I’m feeling a bit lazy today, but here are a couple of quick links. A bunch of the studies reqire memberships in various things to access.

Interesting chart for areas in general. See Spatial Reasoning, especially.
http://www.polymath-systems.com/intel/essayrev/sexdiff.html

http://links.jstor.org/sici?sici=0022-0655(198721)24%3A1%3C65%3AMDISAA%3E2.0.CO%3B2-L

Note the comments in textbook design on page 372: http://books.google.com/books?id=ktDW9UWraeQC&pg=PA372&lpg=PA372&dq=%22spatial+reasoning%22+female&source=web&ots=_WyoSJqbIf&sig=5aKxjKQISJISb_gRUZGV4ZiDZCk&hl=en

[USFRIENDINVICTORIA]

Thanks for the interesting references.

The second one seems perfectly consistent with the hypothesis of bigger differences at the extreme right of the curve.

The reference on test design is interesting. I already knew that the tests have long been "re-balanced" to make them more “gender balanced” and “race neutral”. It appears that leaving out questions requiring spatial reasoning is one of the ways to accomplish that.

The re-balancing of the tests makes it almost impossible to have a meaningful discussion about I.Q.