Evolving honest communication systems: Kin selection and 'mother tongues

In a famous passage, J B S Haldane (1955) conveyed the seed of the idea of kin selection when he acknowledged the selective advantage of saving, at risk to his own life, drowning brothers or cousins, but not more distant relatives. In an odd turn for so insightful a biologist, he then concluded that it was highly unlikely for such logic to explain known examples of altruism. Haldane's reasoning was simple and logical: in a large population the average relatedness would be much smaller than the 1 in ten risk of drowning, and it would indeed be unprofitable, genetically speaking, to jump to the aid of a randomly-chosen individual. What is peculiar is that Haldane overlooked the fact that a "gift " of altruism, if bestowed selectively to closely-related kin, could easily be selected for, thus leaving it to Hamilton (1964) to comprehend and formalize inclusive-fitness theory, and make the most significant contribution to evolutionary theory since Darwin. Indeed, such "altruistic " acts need only satisfy Hamilton's famous equality Br> C, (the Benefit to kin, as diluted by their fraction of relatedness r, must exceed the Cost to self), for selection to favor the action. Perhaps Haldane's reluctance to acknowledge this possibility was influenced by his own rather unusual experience of twice saving a drowning individual, when he gave no conscious thought to relatedness. The unsavory implications of doing otherwise were resurrected by the term "nepotism " associated with early experimental work on kin selection in the 1970's (e.g. Sherman, 1977). Perhaps distaste for nepotism partially accounts for the fact that kin selection has only slowly begun to be integrated into mainstream theory on th