The biological basis for justice and altruism-part 1

(An expanded version of a talk given at CWRU’s Share the Vision program, Severance Hall, Friday, August 26, 2011 1:00 pm. This program is to welcome all incoming first year students. My comments centered on the ideas in the common reading book selection Justice: What’s the right thing to do? by Michael Sandel.)

This year’s common reading book assumes that there is something fundamental about justice that makes its desirability self-evident. What the book discusses are three approaches to justice: the first based on the greatest happiness for the greatest number, the second on respect for the freedom of choice of individuals, and the third on the cultivation of virtue and the common good.

In this talk, I want to examine the very premise that justice is something desirable. What makes us think that people want or seek justice as an end in itself and that the only problem is how to implement that ideal in specific situations? For example, John Rawls’s model of justice (as elucidated in his book The Theory of Justice) assumes that when people are given the opportunity to design a society under the veil of ignorance so that no one knows what situation in life they personally will be placed in, they will create one that is based on the idea of ‘justice as fairness’. Is Rawls justified in assuming that? Is it self-evident that justice is such an obvious good thing that people will want to use it as a central organizing principle?

We may think that it is obvious but one of the characteristics of academia is to not accept things just because they seem obvious and instead look for underlying reasons.

It turns out that there is a solid scientific basis for the desire that humans have for justice and it arises from the theory of evolution. This may come as a surprise to those who think of evolution as based on fierce competition for survival in which justice and fairness plays no role. But in fact, not just justice but also altruism, which can be roughly defined as an act that benefits someone else at a personal cost to us, has been studied extensively and we think we know how it originated biologically.

In his landmark book On the Origin of Species, Charles Darwin carefully avoided all discussions of human evolution, limiting it to just one statement near the end: “Light will be thrown on the origin of man and his history.” That has to rank as one of the greatest understatements ever. It turns out that the theory of evolution, in addition to providing explanations for the physical features of all life, is increasingly explaining our morality as well. The basic desire for justice is ingrained in us as a result of biological evolution.

The reason for this, as was developed over fifty years ago and summarized by Richard Dawkins in his classic book The Selfish Gene (1989), is that while natural selection acts on the whole organism (whether human or fish or snake), the fundamental unit of evolution is not the whole organism but the individual gene, and evolution can be understood as the means by which individual genes try to maximally propagate themselves. But while organisms are unique in the particular combination of genes they possess, each individual gene is shared by many people, with the closer the relationship, the greater the number of genes being shared. So each one of us shares exactly half our genes with our parents and (on average) half with our siblings, one-eighth of them with our first cousins, and so on, with the fraction shared becoming lower the more distant the kin. As biologist W. D. Hamilton showed, as a result there are circumstances in which can be beneficial for a gene if the organism in which it exists sacrifices its own needs to benefit its relatives. When the eminent population geneticist J. B. S. Haldane, who pioneered a lot of the mathematical studies in this area, was asked if he would give his life to save his brother, he jokingly replied, “No, but I would to save two brothers or eight cousins.” In short, the mathematics of genes can favor a limited form of self-sacrifice among relatives and so we should not be surprised if that gene is widely present.

But this kind of altruism, known as kin altruism, is just one form of it. Another important form that was shown by Robert Trivers to be biologically based is reciprocal altruism whereby an organism will do a favor for another that is not a relation in the expectation that in its own time of need the favor will be returned. Take vampires, which seem to have grabbed the public’s imagination for some reason and are now all over popular culture. Vampire bats need to drink some blood every day or they will die. But in bat colonies it has been observed that those who return after having obtained a good meal will regurgitate some of the blood to a less fortunate unrelated bat and in return will receive blood from that bat on the days that they are unlucky.

This kind of behavior has been observed in a wide range of animals, and is another source of the idea that our desire for justice has biological roots. Reciprocal altruism only works if people carry out their obligation to return favors. If cheating or other forms of selfishness occur, the system breaks down and so it should not be surprising that quite elaborate structures have evolved in the animal kingdom, of which we are a part, to monitor behavior so as to reward good citizens and punish cheaters, so that the community as a whole benefits.

This sense of fairness and justice even extends to larger groups. For example, there is a remarkable video of penguins in the Antarctic, where temperatures can reach minus 50 degrees Fahrenheit with wind speeds greater than 100 miles per hour. How do they survive in such bitter conditions? They do so by large groups of thousands of them huddling together very closely at a density of about 2 animals per square foot. The temperatures in the inner regions of the group can rise up to our human body temperatures, which is nice and pleasant. Of course, the penguins on the outer rim of the group will be cold but what the video shows is that the density is just sufficient to provide warmth while at the same time allowing for a constant shuffling around. The penguins all face in roughly the same direction and penguins enter at the rear and then slowly work their way to the front and then return to the rear. As a result, each penguin spends a small time on the cold outer rim in return for much longer times in the warmth inside and thus everyone benefits.

Similar cooperative behavior is seen in locusts and fish schools. It is quite remarkable how widespread such practices are in nature.

Next: More evidence from nature


  1. says

    Martin Nowak, a professor of biology and mathematics at Harvard, recently published a book entitled SuperCooperators. He posits cooperation as the third fundamental of evolution, behind mutation and selection, and talks about five cooperative strategies, including the ones you have mentioned above.

    This is, of course, supremely relevant to our current predicament, as Social Darwinism seems to be experiencing something of a recrudescence. If we could prize cooperation over competition, based on a more accurate understanding of successes in the natural world, we would allocate resources very differently. Sadly, the only cooperation we’re seeing now is among members of the oligarchy -- the penguins who always manage to stay at the warm end of the huddle!

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