Final answer:
The author introduces the idea that an individual's susceptibility to catching a cold depends on one's stress levels, genetic predisposition, and environmental factors, with each of these influencing the immune response.
Step-by-step explanation:
In the text “Why Some People Catch a Cold and Others Don't,” the author introduces the idea that catching a cold depends on an individual's body and health by discussing the various factors that make people more susceptible to catching a cold. These include stress levels, genetic predisposition, and environmental factors. Specifically, researchers have pointed out that stressed individuals are more likely to catch the common cold due to the adverse effects stress can have on the immune system. By bringing up the topic of stress, the author suggests that internal states, such as one's psychological health, can impact physical susceptibility to illnesses. Furthermore, the mention of genetic diseases suggests that our DNA can influence our likelihood of getting sick, indicating a genetic factor in disease susceptibility. The concept of an individual's immune response is also touched upon, which underscores the complexity of the body's defense mechanisms against viral infections. Lastly, environmental conditions, such as dorm room temperature, are proposed as potential contributors to the spread of the common cold among populations like college students.