The more complaints people have, the more psychosis genes they are likely to have inherited, and the more likely it will be that some of those genes will be shared by close relatives. Because of the role that other factors play in each complaint, an affected person’s close relatives may not experience the same complaint. However, if they have a sufficient number of psychosis genes, enough may be expressed as complaints to enable them to meet the criteria for a global diagnosis. As a consequence, the diagnosis will appear to be more heritable than each of the complaints.
