Like everyone, teenagers need nutritious food to stay healthy. Most American teens probably consume too much soda, chips, and other junk food. But have you ever tried convincing a teen to eat better? Perhaps you remember back to your high school health classes: You may not have been convinced when the adults in charge tried to persuade you to eat less junk food and more fruits and vegetables.
One new study tried a different approach, as summarized in this journalist's report. Researchers tried to take advantage of teenagers' disregard for authority figures, making healthy eating seem like an act of defiance.
According to a new study from the University of Texas (UT), ... teenagers can be encouraged to eat healthy foods if they see doing so as a way to rebel against authority....the research suggests that informing teenagers about the manipulative tricks used by big companies to sell junk food reduces their taste for unhealthy snacks.
Study co-author David Yeager [said] “If the normal way of seeing healthy eating is that it is lame, then you don’t want to be the kind of person who is a healthy eater. But if we make healthy eating seem like the rebellious thing that you do, you make your own choices, you fight back against injustice, then it could be seen as high status.”
To test their hypothesis, the researchers conducted two studies on teens aged 13 to 15.
The teens were randomly split into two groups, with one being assigned an article to read on the long-term health benefits of eating a balanced diet. The other group read an expose on the manipulative techniques used by the food industry to sell unhealthy products, such as deceptive labelling and advertising that targets children from poor backgrounds.
The next day, in an unrelated class, the teenagers were each given a snack-pack as a reward from their headteacher for hard work. They could choose the contents of the pack themselves, deciding between snacks like Oreos and Doritos, or healthier options such as carrots and trail mix.
...Just 43 percent of the teens who had learned about the sneaky tricks of the food industry chose unhealthy options, compared to 54 percent of those who had received the health-related information the day before. There was a smaller decrease in preference for sugary drinks but overall, the sugar content of the food-industry-woke teens’ snacks was reduced by 9 percent.
a) What kind of experiment is this? Posttest only? Prettest posttest? Repeated measures? or Concurrent measures?
b) What are the IVs and DVs in the design? (Hint: There is more than one dependent variable.)Is the independent variable manipulated as independent groups or within groups? What keywords in the description tell you how the independent variable was manipulated?
c) Sketch a small graph of the study's results. Pick one of the dependent variables to graph.
d) What do you think? Can this study support the causal claim that "reading an article about the manipulative techniques of the food industry causes teens to select more healthy snacks"? Apply the three causal criteria of covariance, temporal precedence, and internal validity.
