Final answer:
The Genain quadruplet most affected by schizophrenia is Nora, who was not listed in the given options. Research, including studies by Tienari et al. (2004) and Khashan et al. (2008), demonstrates the importance of both genetic predisposition and environmental factors in the development of schizophrenia, with significant differences in outcomes depending on whether the individual was raised in a disturbed or healthy familial environment.
Step-by-step explanation:
The Genain quadruplets are a famous case study in the field of psychology and genetics, particularly regarding the study of schizophrenia. The quadruplet most affected by schizophrenia is Nora (not listed among the choices a-d), with the other sisters being Iris, Myra, and Hester. Each sister exhibited varying degrees of the disorder, which has led to significant research and discussion about the interaction of genetic predisposition and environmental factors in the development of schizophrenia. Regarding the impact of genetics and environment, it's important to consider the findings from the 2004 study by Tienari et al., which showed that adoptees with a high genetic risk for schizophrenia (biological mothers with schizophrenia) were much more likely to develop the disorder if raised in a disturbed family environment compared to a healthy one.
The risk of offspring schizophrenia following antenatal maternal exposure to severe adverse life events was also found to be higher according to a study by Khashan et al. (2008). These studies contribute to our understanding of schizophrenia by highlighting the significant role that both genetic and environmental factors play in the development of the disorder. They seem to support the view that gene-environment interactions are complex and critical in understanding the manifestation of schizophrenia.