Answer to Question 1
Social stress can lead to bad health via suppressed immune function.
Answer to Question 2
Pavlov first introduced a stimulus of food to a dog, and immediately the dog would begin to salivate. Pavlov then introduced a sound simultaneously when he introduced the food and the dog still responded with salivation. Finally, Pavlov introduced the sound without the presence of the food and he found that the dog was conditioned to salivate to the sound alone because it associated the sound with the food. Most experts agree that people are conditioned to a large extent. We respond to stimuli in our environment in learned ways that are almost automatic. However, we can retrain ourselves to respond in ways that are more productive and less stressful.
