In the United States in 1900, about 1 in ___ people in the general population were older adults; in 2010, about 1 in ___ people belong to this group; and by 2050 this group is expected to comprise 1 of every ___ U. S. residents

A trait, which is not inherited, is

a. muscle composition and reflexes. b. energy level. c. cultural norms. d. psychological makeup. e. gender.

One longitudinal study depicted in this chapter that assessed aggressive behavior over a 22-year time period found that

A) children who were aggressive at age 8 were more likely to be convicted of criminal offenses later in life. B) children who were aggressive at age 5 were more likely to be involved in domestic violence later in life. C) children who were aggressive at age 10 were more likely to be watch violent television shows and movies later in life. D) children who were aggressive at age 3 are likely to have a genetic component to their aggression.