[Solved] A two-year account of the progress of a manic-depressive patient who is undergoing psychiatric care is an example of a A) field experiment. B) case study. C) systematic observation. D) naturalistic observation. Erotic Plasticity: The degree to which an individual's sex drive can be changed by social, environmental, and situational factors. Fraternal Birth-Order Effect: The observation that a man is more likely to be homosexual the more older brothers he has from the same mother. Older Brothers: Typically refers to male siblings who are born before other children in a family, often associated with roles of protection, mentorship, and influence in the sibling relationship. Prenatal Development: Prenatal development refers to the process of growth and development within the womb from conception to birth.