You were involved in this paper, it appears.
This paper, Joseph (2015) comes out of the "National Human Genome Research Institute". It trashes twin studies, which is unfortunate because the large twin study, Hallmayer (2011) found autism to be substantially environmental, not as genetic, as heavy advertising claims.
Joseph (2015) is substantially tied to one false statement:
"...heritability... unexplained... is important because a substantial proportion of individual differences in disease susceptibility is KNOWN to be due to genetic factors..." [caps mine]
That statement is false because few diseases can be "known to be due to genetic factors", when environmental toxicology is omitted from their clinical diagnostics, as is very often the case.
Environmental data undermines profit.
"The authors declare competing financial interests" in the final published paper.
What are those please?
A paper we have published in Logos examines the assumptions underlying twin studies. It should be of interest to anyone who cares about toxicological/environmental/social/stress/etc. effects on human health:
by Jay Joseph, Claudia Chaufan, Ken Richardson, Doron Shultziner, Roar Fosse, Oliver James, Jonathan Latham, and John Read
Published in Logos (Vol 14) 2015.
Summary: Classical twin research has been one of the most influential research methods in all of biology. Twin research is based on the proposition that human twins can be either monozygotic (genetically identical) or dizygotic (share 50% of their genes) and this genetic difference can be used to infer the magnitude of a putative genetic component contributing to any physical or behavioural trait. Based largely on many thousands of such studies, which usually show that monozygotic twins are significantly more alike than are dizygotic twins, the scientific community at large has concluded that there is a strong genetic component to many human attributes. Characters for which such conclusions have been reached include practically every familiar physical and mental illness (including heart disease, diabetes, Parkinsonism, ADHD, etc.) and also human behaviours such as IQ, voting preferences, and criminality.
The flaw in this logic, which is outlined in this paper, is that this twin methodology makes use of improbable assumptions. Most notable of these is that the environments of monozygotic and dizygotic twins are identical, and in particular that the environments of monozygotic twins are not more alike. This particular assumption is called the equal environment assumption (EEA). This assumption has never been proven. On the contrary, it can clearly be shown to be often false. This casts grave doubt on ALL twin study findings.
The genetic explanations extrapolated from twin studies have almost never been supported by actual positive findings of significant gene variants in human populations (e.g. Manolio et al., 2009). This failure provides another reason to suppose that the twin method is flawed and we propose that this faultiness lies with the equal environment assumption. In other words, the explanation for the higher similarity of monozygotic twins compared to dizygotic ones is not their genes but their more similar environments.
In this paper, we examine the specific flaws in the EEA from the perspective of criminology, but equivalent or identical arguments apply to all twin research. The scientific implication is that most human variation results from environmental variation in physical, chemical, and social factors (or chance) and not from variation between genes or genomes, and that all twin research is effectively worthless. More broadly it also follows that society has been erroneously led by genetic researchers into a genetic determinist mindset that bears little relation to reality.
Manolio T. et al. (2009) Finding the missing heritability of complex diseases. Nature 461: 747-753.
Jonathan Latham, PhD
The Bioscience Resource Project
Ithaca, NY 14850 USA
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“The conscious and intelligent manipulation of the organized habits and opinions of the masses is an important element in democratic society. Those who manipulate this unseen mechanism of society constitute an invisible government which is the true ruling power of our country.”—Edward Bernays, Propaganda