Final answer:
Psychiatric illnesses are common, usually harmful for reproductive success, and have heritable aspects. Genetic diseases are inherited through family genes, and individual outcomes can vary based on personal genetics and environmental interactions.
Step-by-step explanation:
To address the questions about psychiatric illnesses:
- Psychiatric illnesses can be considered common since debilitating mental disorders affect approximately 1 in 17 people.
- These illnesses are generally harmful for reproductive success due to the challenges they create in various aspects of life, including social and family relationships.
- Heritability is a key aspect of psychiatric illnesses, as there are genetic components to disorders like depression and schizophrenia.
Genetic diseases are passed through family lines due to the inheritance of specific gene variants. For psychological disorders, the underlying genetic architectures are often complex, involving multiple genes and their interaction with environmental factors. The extent to which a disease affects an individual can vary based on their unique genetic makeup. Conditions like childhood obesity may have a psychological basis, further complicated by environmental and psychosocial factors.