A cross-sectional study is one that takes place at a single point in time

Psychologist Ravenna Helson found that women finding a spouse and embarking on what Helson called traditional feminine behavior occurs from ages

a) 16-21. b) 21-27. c) 25-30. d) 30-35.

Adolescents who have serious sleep problems are more likely than average to become depressed later

a. True b. False Indicate whether the statement is true or false