The term was popularized by researchers like Gottesman and Shields in 1973 to describe heritable traits in psychiatric conditions like schizophrenia.
Historical context
regarding sleep cycles and "early awakening" in relation to environmental stressors or physiological development in children. Germ-Free Connection: Some modern and vintage studies use germ-free animal models early awakening report 14 and under 1973 germ free
Outcomes and follow-up