Each human being could be placed on a continuum somewhere between superfeminine to hypermasculine. Placement depends on the amount and timing of hormones to which the fetus was subjected during pregnancy. (Fisher, Helen, PhD. The First Sex. p xviii-xix. NY:Random House, 1999.)

Males and females could be placed on a continuum, including females with male-differentiated brains, males with female-differentiated brains, and people with ambiguous brain-body differentiation. (Howard, Pierce J., PhD. The Owner’s Manual for the Brain. p 215-218. GA: Bard Press, 1994, 2000.)