According to evolutionary theory on kin selection, monozygotic (identical) twins should help one another more than dizygotic (fraternal) twins

Rates of overweight and obesity have increased in the U.S. in recent decades because of genetic changes in the population.

a. true b. false

Which of the following is an accurate description of partner relationships in later life?

A) According to research, marital satisfaction is lower in the late adult years than when children are still at home. B) Older adult couples typically are not sexually active. C) Older couples report lower levels of conflict in their relationships than do middle-aged couples. D) Married older adults who spend less time with their spouses report high levels of happiness.