1. Explain what it means to say that addictive drugs “hijack” the reinforcement system.

2. Although executives of tobacco companies used to insist that cigarettes were not addictive and asserted that people smoked simply because of the pleasure the act gave them, research indicates that nicotine is indeed a potent addictive drug. Why do you think it took so long to recognize this fact?

3. In most countries, alcohol is legal and marijuana is not. In your opinion, why? What criteria would you use to decide whether a newly discovered drug should be legal or illegal? Is there a danger to health? What are the effects on fetal development? What are the effects on behavior? Is there a potential for dependence? If you applied these criteria to various substances in current use, would you have to change the legal status of any of them?