Because children develop increasingly more complex cognitive abilities as they move through middle childhood, older children are more likely to have friends of ethnicities different from their own than are younger children

A new testing technique that supports the hypothesis that group differences are attributable to environment uses which of the following procedures?

a) The goal and format of the test is explained first. b) The children are tested in quiet rooms. c) Everyone is told that intelligence is not genetic. d) Students are given a high-energy snack first.

Some researchers think that _________ provides a means for an infant's brain to stimulate itself

a) SIDS b) rhythms c) autostimulation d) state