Difficulty in managing ADLs increases markedly after age 85 . Which of the following is a leading factor in postindustrial countries?

What has research shown about "far transfer"? a. It never occurs

b. It is generally a small, inconsistent effect. c. It occurs in older people, but not in children or young adults. d. It is a strong, robust phenomenon in almost all cases.

The main reason it is not possible to determine causality from a correlation is:

a. the investigator actively manipulated the environment b. the presence of potentially uncontrolled factors c. researcher bias d. reactivity