Is the Individual Idiolect Substantially a Genetic Inheritance?

Abstract Although stylometric studies tends to situate itself within the field of forensic analysis, most stylometricians appear averse to considering genetic explanations for their findings. Instead, they try to work with a range of what they construe as environmental factors in attempting to understand the clustering of individual authorial idiolects. However, researchers in behavioral genetics have demonstrated that the traits for cognitive abilities, including language ability, are among the most heritable. In this paper, I set out the major postulate and eight corollaries for the genetic hypothesis and the major postulate and five corollaries for the environmental hypothesis for explaining the clustering of individual idiolects in dendrogram analysis, using stylo in R. Using a corpus of Anglo-American modernist poetry, I then demonstrate that the individual idiolects of each of the Sitwell siblings—Edith, Osbert and Sacheverell—cluster together. In this way, I aim to help researchers decide which of the two hypotheses is the most likely explanation for the attested idiolectal similarities among the members of a number of important British and French literary families.