Because it has its own endogenous receptor system, marijuana does not appear to involve mesocorticolimbic dopamine neurons

Which of the following statements about friendships during midlife is true?

A) The number of friendships increases with age. B) Middle-aged adults attach less value to friendship than younger adults. C) Older adults work harder to initiate new friendships than younger adults. D) Friendships become more selective in midlife.

In the United States, ____ Americans tend to score highest on intelligence tests

a. European b. African c. Asian d. Hispanic