True or False: if false, choose the answer that best corrects the statement.
Circadian rhythms describes the variation in body temperature.
A psychologist observes a group of 6-year-olds and a group of 10-year-olds during recess at school in order to assess changes in playgroup preferences between these two ages. This researcher's study uses a _____ design.
cross-sectional
longitudinal
cross-sequential
cross-longitudinal