Adanish adoption study compared at-risk adopted children who had biological mothers with schizophrenia to a control group of adoptees whose biological mothers did not have schizophrenia. when the environmental factor of communication deviance was assessed and compared with the two groups, it was noted that

I believe the answer is: children who were at genetic risk and who lived in adoptive families with high communication deviance showed higher levels of thought disorder when compared to control children.

The purpose of the initial research is to know whether there is a separate role of nature (genes) and nurture (the environment) in the development of schizophrenia. Up until this day, scientists still haven;t figured out the sure answer for this question.