"While it appears that genetics play a strong role in a person's risk for schizophrenia, environmental factors may play a role in whether the disease manifests itself," writes Lane Wallace.
The researchers wanted to find what it was about urban living that increased the risk. The factor that showed the strongest correlation was later termed "social fragmentation." "In very stable, homogeneous communities (often the case in more rural environments), the social norms and bonds are very consistent and strong. But in urban environments, where there tends to be much more diversity and movement within communities, social ties are often more fragmented. And that fragmentation is felt most among people who move often, or feel like "outsiders" in a particular community."
Dr. Stanley Zammit, who headed the study out of Cardiff University in Great Britain, emphasized that we should not draw too many conclusions from just one study and more research is needed. It is also important to bear in mind that while correlation is important it doesn't prove causality.