1. Dieting Aids
Recovering from a mild dose of food poisoning I note how my appetite has quite gone - the infamous 'illness diet'. Isolating the appetite-suppressing hormone involved would be the ultimate dieting aid, so how hard could it be? Very.
Stephen Pinker (in The Blank Slate) noted that monogamy has nothing to do with women's rights but is instead a conspiracy of weak men against the strong, so that every male gets a mate. He argued that most women would prefer to be the second wife of President Bill Clinton than the first wife of Bobo the Clown.
In fact, monogamy seems mostly to suit sedentary farmers and was adopted in European agrarian societies in the Dark Ages, if not before. Nomadic pastoralists are typically aggressive with an 'honour culture' involving high rates of inter-male violence, and presumably mortality. Is it any co-incidence that such cultures neither prescribe nor practice monogamy? Think the Arab tribes which were organised under Islam (four wives), or the Mongolian steppe nomads with their vast harems. Big problem when they settle down.
And don't get me started on selective female abortion (China, India) resulting in way too many males.
Most males have a negative emotional reaction if their wife conceives a child by an unrelated male. The child is a cuckoo in the nest - the genetic implications are obvious.
Some time in the future, it will be possible for Mr and Mrs Average to have their gametes combined by a company which will sequence the pre-foetal DNA and make allele changes for improved health, beauty, intelligence and character. The resulting optimised offspring might well be genetically further from the father than that resulting from any conceivable adulterous mating by his wife.
How, actually, is he going to feel about that?