well , too little of a discussion,
the theory, as it asserts normative homosexuality among humans through 'non existence of sexual instinct', essentially negateting the need for male female interactions.
i have questions
1. does human sexual instinct exist ?
2. the existence of two distinct sexes, is , perhaps itself human sexual instinct, isn't it ?
the difference between physical and mental aspects of both the sexes may be is an ' 'instinct' like ' itself i.e the opposite sexes should have greater curiosity of exploration, therefore greater drive towards each other and attraction, after all attraction is continued curiosity. and i base this upon on genders, i do think gender has much too do with current sex than what is going in brain.
3. and is recreational sex between male and female possible, without using any external contraception ?
the author uses this to establish higher homosexual interactions than heterosexual ones. derives the result - normative homosexuality
{ though intelligence, thinking ability, is too natural extenstion, and i suppose invention of condoms is natural too, as opposite sex gives more 'thrills', another step towards complexity, greater interactions with the other of species. }
and i suppose maybe the whole theory is built up on like this :
'no' sexual instinct in humans,
same sexes being like minded ,
have more chances of interactions ( essentially overlooking the fact curiosity towards opposite sex )
no natural contraception, therefore no recreational heterosexuality ( prepubersent female bonobos have sex with older males and about sex after menopause )
( i personally donot think ejaculation is much of a involuntary process )