In a research study, a psychiatrist gives depressed patients a particular drug and observes that their symptoms diminish. He concludes that the drug caused the reduction in symptoms. This experiment is flawed because it lacks ______

People who choose NOT to have children tend to:

a) be just as well-adjusted as parents. b) regret their decision in old age. c) have more unhappy marriages than parents. d) be more self-centered than people who are parents.

Peer collaboration is often unproductive. Which of the following is NOT one of the reasons why peer collaboration may fail?

a. Collaboration involving young children often fails because young children may lack the social and linguistic skills need to work as part of a team. b. Collaboration involving young children often fails because the problems are so difficult that neither child has a clue about how to proceed. c. Collaboration involving young children often fails because both children are invested in solving the problem, so there is competition for who should get to do the majority of the work. d. Collaboration involving young children often fails because children are often exposed to instruction, which emphasizes individual achievement rather than collaboration.