Your review of Donald Pfaff’s Man & Woman: An Inside Story (Oxford: Oxford University Press, 2011) focuses on the science of sex determination (“Fluid Movement,” January 1, 2011). A neurobiologist of note from New York’s Rockefeller University, he argues that this is a process that is not over by birth, but continues through puberty. Also, strongly masculine and strongly feminine genders mark each end of the spectrum. In between, every permutation is possible, as is the case with sexual orientation. Thus a gender continuum. Significant differences between men and women only pertain to “primitive” behaviors including mating, parenting, and aggression. When it comes to “higher functions,” which arguably make us human, the similarities outweigh the differences. Quite enlightening, this. I only wonder how the higher functions are propagated through generations if they have little or nothing to do with primitive behaviors, and especially mating and parenting. Is this yet another attempt to poke fun at good old Darwin by sneaking “culture” in through the back door?