Jill Neimark in Aeon:
The evolutionary biologist Robert Trivers, a professor of anthropology and biological sciences at Rutgers University in New Jersey, is one of the most influential thinkers on evolution today. Four decades ago, he published a series of papers that teased out the intricacies of our relationships with parents, children, lovers and friends, and laid the groundwork for a Darwinian social theory. His hypothesis about reciprocal altruism explains the profound puzzle of why we help others who are not biologically related to us, even to our own temporary detriment. Quite simply: we expect that the other will return the favour at a later time. Trivers’s ingenious conception of parent-offspring conflict proposes that parents will want to invest equally in all their children (since they are all equally genetically related to the parent), while siblings will each try to get more of their parents’ investment, to the disadvantage of their brothers and sisters. He also came up with a novel explanation for why we so frequently deceive ourselves: the most convincing liar is one who believes his own lies. In the words of the cognitive scientist Steven Pinker at Harvard University: ‘It would not be too much of an exaggeration to say that [Trivers] has provided a scientific explanation for the human condition: the intricately complicated and endlessly fascinating relationships that bind us to one another.’ Trivers’s latest book, a memoir entitled Wild Life: Adventures of an Evolutionary Biologist, is published this month. Here, he discusses his two decades of research on symmetry, a phenomenon that seems to span all of nature, from physics to biology to art and architecture.
When you use the term symmetry to describe life, what do you mean?
Trivers: I am referring to bi-laterally symmetrical creatures, that is, creatures that have an imaginary line running down the middle of the length of their body – distances from this to a place on each side are symmetrical if they are identical. Likewise, you can compare elements on each side, let us say, ears, and ask if length and/or width are identical.
What captivates you about symmetry?
Trivers: It’s very simple: it is the only trait in which we know what the optimal value is. We might think your kidneys look perfect, but we don’t have an actual measure for the optimal kidney. So we can never say that you have managed to create the ideal kidney your body was aiming for genetically, in spite of the early perturbations and stresses experienced during development. We just don’t know.