Running Head: Gene x Antisocial friend interaction on Reading Comprehension Examining transactional influences between reading achievement and antisocially- behaving friends

Background. The association between poorer academic outcomes and having antisocial friends is reliably demonstrated yet not well understood. Genetically sensitive designs uniquely allow for measuring the areas of genetic vulnerabilities and/or environmental risk in the association of antisocial friend behavior and poor school achievement, allowing for a better understanding of the nature of the association which is otherwise not available. Methods. The present study included 233 pairs of twins (mean age=10.71, SD=1.06) from the Florida Twin Project on Reading. First, the role of antisocial friends as an environmental moderator of reading comprehension was examined. Second, the role of reading comprehension as an environmental moderator of antisocial friends was examined. Results. In the first model, antisocial friends significantly moderated the nonshared environmental variance in reading comprehension, with increased variation at lower levels of association with antisocial friends. The genetic correlation in this model was -1.00 throughout the range of antisocial friend behavior, indicating substantial niche-picking. In the second model, reading comprehension significantly moderated the nonshared environmental variance in associating with antisocial friends, with increased variance at lower levels of reading comprehension. Additionally, there was a moderate and constant positive genetic correlation, indicating common genetic influences contributed to higher reading achievement and better-behaved friends. Conclusions. These results suggested reciprocal influences between reading achievement and antisocially-behaving friends. Antisocial friends appeared to be limited in the extent to which they can undermine reading achievement. At the same time, high reading achievement appeared to support less association with antisocial friends. Together, these results tell a mostly positive story concerning the transactional relation between