Answer to Question 1
Some psychologists have speculated that decreases in the amount of animal research has resulted, in part, from a change in theoretical perspectives, from behaviorism to cognitivism. Behaviorists were willing to generalize to people from animals, cognitive psychologists less so.
A second reason is that psychologists have turned their attention to different research questions, ones that are less likely to be answered through animal research. Part of this may be due to the increasing number of women in psychology.
A third reason is that people, including psychologists, are more sensitive to the ethical issues associated with animal research.
Answer to Question 2
Goldenberg et al. (1999) used a manipulated variable, whether participants were primed to think of sex or not by the content of a questionnaire. The researchers also identified the level of neuroticism, high or low, in their participants, a measured or quasi-experimental variable.
The investigators found that when the participants saw a group of letters and were asked to filling more letters to create a word (e.g., COFF _ _), the participants in the high neuroticism group were more likely to create a death-related word. If neurotic participants focused on romantic aspects of sex rather than purely physical aspects, they tend to stay away from death-related words.
The three basic body plans of bilaterally symmetrical animals.
Managing large bands of grazing animals requires detailed knowledge of local landscapes, especially
Major Events in the History of Psychology
Functionalist and Conflict Views of Stratification: The Distribution of Society's Resources
Examples of transgenic animals
Cloning animals by nuclear implantation