The question was one of origin. I'm not saying that people who use the phrase today necessarily know of this origin when they use the phrase "give a fig", but the Elizabethans and the Jacobeans knew its obscene meaning (as did D H Lawrence -- of troy, I, too, remember that scene about how to eat figs). And they associated with the Mediterrranean (fig of Spain, etc.) There are other scatological and carnal words that plug into the phrase "give a ____" with similar meaning of 'not caring much or at all'. Jazz used to be an obscenity, and only a few people today know what it meant. Gives new meaning to "all that jazz".