Pulling Back the Curtain on Heritability Studies: Biosocial Criminology in the Postgenomic Era

Invited Address: “The Times They Are A-Changin’” Gene Expression, Neuroplasticity, and Developmental Research

“…This failure has raised serious doubts about the validity of behavioral genetics studies reporting strong heritability for most phenotypes. It appears that the high heritabilities found in these studies were due in large measure to methodological deficiencies associated with the twin study method and to a faulty conceptual model that incorrectly assumed that genes exert main effects that are independent of the effects of the environment (Burt and Simons 2014;Charney 2012) Finally, contrary to the gene-centric model, evidence suggests that only about 2 % of the human genome codes for proteins (Carey 2012), while most of the remaining non-protein coding DNA (what used to be considered junk DNA) is involved in regulatory processes that determine which protein coding segments of a gene will be expressed and the types of proteins that will be produced (Meloni 2014;Pennisi 2012). Such findings have fostered a paradigmatic shift that places less emphasis upon inherited DNA differences between people and more importance upon identifying the epigenetic factors that control or regulate DNA expression.…”

Mathematical Proof Is Not Minutiae and Irreducible Complexity Is Not a Theory: A Final Response to Burt and Simons and a Call to Criminologists

“…" We examined their assertions carefully. We found that Burt and Simons (2014) cherrypicked the studies they cited in support of their position regarding the biasing impact of the equal environments assumption (EEA), something they openly admit in the online supporting information of their rejoinder (Burt and Simons, 2015, this issue). Specifically, they state, "we focused on articles that showed that the EEA is not a valid assumption" to support their claim that heritability estimates from behavioral genetic studies are chronically overestimated as a result of violations of this assumption.…”

“…In addition, as we noted in our comments on the original article by Burt and Simons (2014), they misquoted and mischaracterized scholars, a trend that they continue in their rejoinder (Burt and Simons, 2015). A simple example occurs in the first sentence of their rejoinder, where they allege that they follow in the footsteps of "renowned behavioral geneticists (e.g., Rutter, 1997;Turkheimer, 2011a)" and call for an end to heritability studies.…”

“…In their initial article, Burt and Simons (2014) laid out a range of specific criticisms of twin-based research. They argued that violations of the statistical assumptions that underpin this line of work result in upwardly biased estimates of heritability and downwardly biased estimates of environmental effects.…”

Demonstrating the Validity of Twin Research in Criminology

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In a recent article published in Criminology, Burt and Simons (2014) claimed that the statistical violations of the classical twin design render heritability studies useless. Claiming quantitative genetics is "fatally flawed" and describing the results generated from these models as "preposterous," Burt and Simons took the unprecedented step to call for abandoning heritability studies and their constituent findings.

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