Just-so stories were invented by British writer Rudyard Kipling. Writing for children, he devised amusing and quirky tales about how different animals acquired their distinctive features. The camel was given its hump by an evil spirit for refusing to work because the hump allows it to work for longer without eating, for instance.
Apart from their sheer silliness, the just-so stories differ from science because they are idiosyncratic. A different kind of story is told for each species. Darwin's contribution was to propose an explanatory theory that would work as well for one species as another.
The theory of evolution by natural selection is not just good for explaining why elephants have big ears, but can also explain the big ears of bats, or the small ears of moles. This is exactly the opposite of Kipling with his different "explanation" for every animal's peculiarities. Ironically Darwin's successors are frequently accused of telling just-so stories precisely when they are comparing humans with other species.
Why this happened is hard to be sure but it may well be an example of the Carl Rove effect. This evil genius overcame a weakness of his own candidate by projecting it onto the opponent. If George Bush sat out the Vietnam War while John Kerry served his country, then attack Kerry for disloyal conduct in the course of the war, as in the swiftboat ads.
Consistent with this thesis, one finds that all of the main opponents of evolutionary thinking tell just-so stories all of the time. This is true of religious fundamentalists because they separate humans from the rest of biology. It is true of Communists and socialists because they deny that inherited biological influences really matter in human affairs. Cultural determinists do Kipling all of the time invoking a distinct explanation for human behavior in different ethnic groups, different places, and different time periods
One example of a just-so story that I discredited earlier is the view that People of Scots Irish descent are infected with a "culture of violence," due to their herding antecedents. Another is Susan Brownmiller's thesis that men everywhere are inclined to rape women so as to deny them political equality. Ditto for Margaret Mead's tale that there are no sexual conflicts in Samoa . Or the argument that single parenthood is due to weak "family values" (see The Myth of Culture). Virtually every cherished theory in the social sciences is a just-so story.
I never thought about how shockingly inappropriate the just-so criticism of evolutionists is until I was personally accused of just this failing in a recent scholarly book on physical attractiveness penned by two social psychologists. Specifically, they attacked my suggestion that women today are attracted to moderately big, strong, and muscular male bodies partly because such men would have prevailed over sexual rivals in the evolutionary past.
The authors mistakenly conclude that because I do not have a time machine, I cannot draw any valid conclusions about our evolutionary past. They underestimate the power and subtlety of the comparative method that I used in my 1995 paper.
Instead of producing a quirky story that applies to just one case, my physical attractiveness paper discussed attractive human male bodily features in the same context as the antlers of deer and the colorful plumage of male birds (sexually selected traits that attract females).
A distinct pattern emerges for body size. Among species where males are larger, and stronger, than females this is also due to male-male sexual competition. Their bulk and strength are used to fight off other males so as to inseminate as many females as possible.
Is this a just-so story? No, because it can be, and has been, tested and verified repeatedly using modern data. In species with intense sexual competition, such as elephant seals, the male is very much larger than the female. Among various deer species, those that monopolize a large harem are very much bigger than females whereas smaller harems are associated with a smaller sex difference in size with monogamous deer being of the same size.
Because I considered many other species, I could be confident that the greater size and strength of men than women had to be due to sexual competition operating over many generations. Such generalizations lie at the heart of science. They are the opposite of just so stories that consider each phenomenon in isolation. We evolutionists are not the ones telling the just-so stories.
