The concepts of reversibility and conservation develop during the __________ stage

A researcher finds that there is a relationship between the amount of time college students spend at the library and performance on tests. Specifically, the more time spent at the library, the higher students scored on their exams

This relationship represents what type of correlation? a. A positive correlation b. A negative correlation c. No correlation d. An illusory correlation

Selman's stages of friendship are based upon children's

a. physical abilities, such as gross and fine motor skills. b. popularity with peers. c. levels of independence. d. perspective-taking skills.