John T. Manning

By John Manning, as seen on the bbc's secrets of the sexes here and also here. The strongest evidence was given for the negative correlation between (2nd finger to 4th finger measured base wrinkle to tip) digit ratio and (a) athletic ability and (b) visual-spacial perception (as explained and demonstrated in the video) but here Manning gives the data for numerous experiments relating the digit ratio to various other topics. It's not really suited for the casual reader (and probably not worth reading unless you're super interested), but one can get the gist from reading the preface and skimming the chapter conclusions.
Ch. 1: Males tend to have lower 2D:4D ratio (4th finger longer than 2nd) than women (caused by exposure to higher testosterone levels in utero).
Ch. 2: Lower 2D:4D in males = higher fertility; higher 2D:4D in women = higher fertility.
Ch. 5, 6: Lower 2D:4D in males = possibly higher rates of autism, heart disease.
Ch.7: Gay women tend to have lower 2D:4D relative to heterosexual women; correlations in homosexual males relative to straight males were less clear-cut.
ch.8: explores the effect on musical ability and musical appreciation.
ch.9: athletic stamina, spacial perception, and football… (mehr)