The unbiased description of immediate experience as it occurs is ____

Adoption studies may be flawed because

a. adopted children are more likely than nonadopted children to have genetic disorders. b. the results of adoption studies usually conflict with results of twin studies. c. agencies may try to place adoptees in environments similar to those of their biological parents. d. parents treat adopted children differently from biological children.

Which of the following is both a necessary and a sufficient principle to prove a causal relationship?

a. Where there is the effect, there must also be the cause. b. Where there is no cause, there should be no effect. c. Where there is a change made in the cause, there should be a resulting change in the effect. d. All of these are necessary and sufficient conditions for proving a causal relationship between variables.