by Neil Levy
Neil Levy is professor of philosophy at Macquarie University, Sydney and deputy director of the Oxford Centre for Neuroethics. He is the author of 7 books, including Neuroethics (2007) and Consciousness and Moral Responsibility (2014), and edits the journal Neuroethics. He is also a member of the AJOB Neuroscience board.
A recent study by Rachel Yehuda et al. in Biological Psychiatry provided further evidence for the genetic transmission of acquired characteristics, by showing that Holocaust survivors passed certain acquired genetic markers to their children. The idea that acquired characteristics can be genetically transmitted is (roughly) equivalent to the doctrine of Lamarckism, and was long considered a heresy in biology. [Editor’s note: see also Ryan Purcell’s 2014 post for this blog on the relationship between Lamarckism and epigenetics.] According to the Darwinian orthodoxy, traits change because randomly occurring mutations confer a relative fitness advantage on some organisms, not because they change their behaviour, and that change then comes to be encoded in the genes. But the orthodoxy has long been shattered. Scientists now recognize that the story is a lot more complex than that.
This new study is of central interest to neuroethics for many reasons. One is that the trait in question is psychological, or at least very plausibly underlies a disposition to certain psychological responses, given the right circumstances. Children of Holocaust survivors are themselves at higher risk for stress disorders: a propensity to stress disorders is inherited. How does the inheritance work? One possibility is that their parents behave differently, due to the trauma they experienced, and this difference in how they treat their children causes the difference in susceptibility.
The views, opinions and positions expressed by these authors and blogs are theirs and do not necessarily represent that of the Bioethics Research Library and Kennedy Institute of Ethics or Georgetown University.