Are habits inherited? A possible epigenetic route from Charles Darwin to the contemporary debate.

What is a habit? What do habitual processes and evolutionary theory have to do with each other and what is the role played by habitual processes in heredity? The main aim of this paper is to take a fresh look at Charles Darwin's use of the term “habit”: we shall analyse value and functions of this concept in Darwin's early works, particularly in his Notebooks, and compare these early views to Darwin's more mature understanding of habits in the Origin of Species; most interestingly, we shall discuss Darwin's view on habits in the light of today's theories of epigenetic inheritance, which describe how the functioning and expression of genes is modified by the environment and how these modifications are transmitted over generations. Indeed, current epigenetics seems to revive (at least to a certain extent) Darwin's early ideas on habitual processes. The young Darwin, persuaded, after his Beagle voyage, that species change over time, considered habits as one of the main agents of evolution.