A person experiences too strong a sense of guilt over his fantasies. According to Erik Erikson's theory, he had difficulty resolving the inevitable crisis that occurred when he was ________

Rubella, human immunodeficiency virus, syphilis, and encephalitis are all included in the same section of your textbook because they are all

a. caused by recessive gene pairings. b. infectious diseases that can cause intellectual disability. c. the most common forms of death for people with severe and profound intellectual disability. d. the result of per-natal and perinatal complications.

A rat is placed in a box where the lever works every fourth time. This is a _____

schedule. (a) fixed interval (b) variable interval (c) fixed ratio (d) variable ratio