Reliability is No Vice: Environmental Variance and Human Agency

Charles C. Roseman, Jonathan M. Kaplan

Research output: Contribution to journalArticlepeer-review


The environmental elbow room model of free will posits the unshared proportion of environmental variance in twins is a measure of the degree to which free will may be exercised with respect to one’s life outcomes for a trait. This model attempts to unify the behavioral genetic study of socially important psychological characteristics such as intelligence and academic achievement with Dennett’s broadly compatibilist elbow room notion of free will. We demonstrate that the philosophy and genetics underlying the environmental elbow room model are both fundamentally flawed. Philosophically the degree to which an outcome might be predicted in a given situation does not give any sense of whether the course of action to achieve an outcome was free or unfree. With respect to genetics, quantities such as heritability and its environmental complement, even when they do reflect the actions of independently identifiable causes are not indicative of the chain of decisions one would have to evaluate to judge if an action was freely chosen. We show the contemporary human behavioral genetics focus on heritability is wholly misplaced for purposes of making decisions about policy and free will alike. Variance components sample a single instance of the distribution of variation arising from different sources and do not constrain outcomes in other contexts. The claim that the high heritability of a trait, life outcomes included, makes us less free to change it is similar in key ways to Jensenism’s contention that high heritability makes social change impossible.

Original languageEnglish (US)
Pages (from-to)210-226
Number of pages17
JournalBiological Theory
Issue number3
StatePublished - Sep 2022


  • Agency
  • Free will
  • Genetic determinism
  • Heritability
  • Jensenism
  • Quantitative genetics

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • History and Philosophy of Science


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