LanguageLog urges caution

while reading science articles and reports.From an article on Nature nurture studies of ToM:
"Theory of mind is a term introduced by Premack and Woodruff (1978) to refer to a set of abilities that may be uniquely human: to attribute mental states such as beliefs, knowledge and emotions to self and others; to recognize that the mental states of others many differ from one's own; to use these attributed states to explain and predict behavior; and to predict how such mental states would be affected by hypothetical actions.
....there are many reasons to be interested in "twin studies" that are designed to tease apart the genetic and environmental influences on ToM abilities. And if such studies are set up to distinguish ToM abilities from general verbal abilities, so much the better.
Unfortunately, as we've mentioned a number of times recently, such studies are quite difficult to interpret. And in the course of looking for something else, I recently stumbled over a really suprising example of these problems.
....
I'm going to leave the detailed analysis for another post. But today, I want to set the stage by quoting the quantitative conclusions of two studies with the same first author, published six years apart, which used the same experimental design (ToM and verbal IQ tests on monozygotic vs. dizogotic twins) and the same statistical method (analysis of variance), but came up with radically different estimates of the genetic contribution to individual differences in ToM abilities."