Band Of Brothers?

Altruistic behavior (eusociality) gave Darwin reason to tug at his beard when penning his survival of the fittest concept as the there didn’t seem to be much benefit to altruistic behavior as a common occurrence. When we look across species, it is pretty common.

The cost/benefit analysis was put into nice a nice mathematical expression by Hamilton as
rb-c > 0  where c = cost, b = benefit and r is relatedness.
So this means for a sibling r = ½, for a cousin r = ⅛. The consequence is that your altruism grows with closeness of kinship. This seems to work with computer simulations with hungry robots and some insect colonies. Many students diligently take note of this and include it in their term papers.

            However, all is not quiet and cozy in the recent literature. Nowak et al are strong proponents of using group formation and benefit rather than familial ties as the basis (1). Our armies for example work hard to establish a strong esprit de corps from unrelated people rather than trying to recruit extended families.

            A staunch defense of the original Hamiltonian has been launched by Bourke who defends family ties to the last man standing (2). Again, insects, ants in particular, feature strongly.

As we stand on the sidelines while this ding-dong worthy of Tweedledum and Tweedledee is raging, a curve ball has been tossed into the mix. Kurzban et al have pushed Kant forward to face off with Hamilton (3). So how does nepotistic altruism stack up against Kant’s concept of moral rules derived from common sense ideas of maximizing welfare?

This of course, had to be tested and Kurzban et al set 1290 people the problem of killing one person to save five others. (Note: other options such as waterboarding weren’t a choice.) The relationship of the sacrificial lamb to the test person was varied and their willingness to save the five was recorded.

The results? Are you sure you want them? The researchers found that the participants were more willing to ice a brother or a friend than a stranger to save the five. Clearly, the moral cognition of the 1290 isn’t explained by family ties, or reciprocity, so where does that leave us?

Carrying a big stick, perhaps? I am left with one question: what would a Bonobo do?

  1. M.A. Nowak, C.E. Tarnita & E.O. Wilson, Nature, 1057, 466, (20210).
  2. A.F.G. Bourke, Proc. Roy. Soc. B, (2011) doi: 10.1098/rspb2011.1465
  3. R. Kurzban, P. DeScioli & D. Fein, J. Evolution & Human Behavior

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