Researchers are conducting a study where they have concerns that the participant's beliefs and/or the experimenter's beliefs may skew the results. Therefore, they chose to conduct a ________ study.

In the nineteenth century, the discovery of syphilis helped scientists understand that

a) psychological disorders could be contagious and transmitted through human-to-human contact. b) the spread of bacteria caused most psychological disorders c) mental illness was caused by ruptured blood vessels in the brain. d) a physical disease could cause a psychological disorder.

Advancing age affects

a. both the physical and functional capabilities of the sensory systems. b. muscular strength more than endurance. c. physical appearance more than physical ability. d. highly developed skills that cannot be compensated for by alternate strategies. e. endurance more than muscular strength.