About how many genes are different between any two unrelated individuals?

Amy is very excited for the day of her wedding. On that day, she experiences a spike in happiness and this feeling lasts for about a month. After that, she returns to her "normal" levels of mood. According to the text, what is this an example of?

a. The "marriage effect" b. The "contrast effect" c. Cyclical happiness d. Adaptation

A serotonin agonist would:

a. promote aggression. b. reduce aggressive attack. c. reduce serotonin synthesis. d. increase risk-taking behavior.