The risk of developing schizophrenia shows a strong positive correlation with the degree of genetic similarity to an affected individual. Compared to a 1% risk in the general population, the likelihood increases as follows: first cousins (12.5% shared genes) have a 2% risk; relatives like uncles, aunts, and half-siblings (25% shared genes) have a 3-6% risk. For immediate relatives sharing 50% of genes, the risk varies by specific relationship: parents (6%), siblings (9%), children (13%), and fraternal twins (17%). The risk is highest for identical twins, who share 100% of their genes and have approximately a 48% chance of developing the disorder if their twin is affected.