Ever since she was a few weeks old, shelly has been an unusually contented baby who slept and ate well and adapted easily to new experiences. a developmental psychologist would probably describe shelly's temperament as being:

Martha participates in a research study in order to receive extra credit for her psychology class. when she arrives in the research office she is given a can of what looks and tastes like beer, but which actually contains no alcohol. in the adjoining room martha's classmate karen is also participating in the study. karen receives a can of alcoholic beer. if the experiment was designed to test the effects of alcohol on concentration, then who is exposed to the independent variable?