The following fictitious news accounts suggest causal relationships from non-experimental data. Pick 2 of the 4 studies. Then, for each of the studies you select, think of an explanation for the results other than the one suggested in the headline.
Study 1: Living Together Leads to Divorce: Don't live together if you want to stay married. So says a nationwide study of over 2000 couples. The study found that couples who had lived together before getting married were 2.3 times as likely to get divorced as couples who had not lived together.
Does living together before marriage lead to divorce? How else can this finding be explained?
Study 2: TV Watching Causes Obesity: "Turn off the tube," says the American Academy of Pediatricians. "Watching TV causes obesity." A study conducted for the Academy found that fourth graders who watched more than 25 hours of television a week weighed, on average, eleven pounds more than fourth graders who watched less than 25 hours. The Academy advised parents to severely restrict their children's television diets.
Does watching TV cause obesity? How else can this finding be explained?
Study 3: Pizza Cures Cancer: Head to the nearest Pizza Hut! Researchers have found that eating pizza and spaghetti sauce can protect against cancer. Seriously! A university study of the eating habits 47,000 men over six years found that those who had at least 10 servings of tomato- based foods a week were up to 45 percent less likely to develop prostate cancer.
Does eating tomato-based foods reduce the risk of cancer? How else can this finding be explained?
Study 4: Small Colleges Drive Students to Drink: Parents around the country are withdrawing their children from small colleges. Their action comes after release of a survey last week which found that students attending small colleges (less than 2,000 students) consumed an average of 7.2 alcoholic beverages a week. By comparison, those attending large schools (more than 20,000 students) consumed an average of 4.5 alcoholic drinks. Parents speculated that pressures of the small college environment were pushing their children to drink.
Does attending a small college cause students to drink? How else can this finding be explained?
Study 1: This is a correlation, it doesn't establish any direct causal link; even if there is a direct causal link it doesn't establish the direction of causation. There may be a causal link between livingAlternative explanations for the correlation:
1. The couples who live together prior to marriage likely have more socially liberal views on marriage to begin ...
Analysis of whether the reported conclusions of two studies actually demonstrate a causal relationship. Alternative causal relationships explored, as well as the significance of correlation. Specific discussion of effect of TV watching on obesity and the effect of cohabitation on divorce rates.