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The online magazine Study Finds has a new summary of a developmental psychology study. The headline focuses on the relationship between childhood screen time and teen depression. But another major result of the study found a relationship between childhood physical activity and teen depression. We'll focus on that here.
Here's some detail from the article:
The eight-year study, which tracked children from elementary school into adolescence, found that kids who racked up more screen time—especially on mobile devices—showed higher levels of stress and depressive symptoms as teenagers.
This study has a longitudinal design, apparently ("The eight-year study, which tracked children...") tells you so.
Now for the method and results. I'll join you on the other side.
Study authors used data from the Physical Activity and Nutrition in Children (PANIC) study, which followed 187 Finnish children over eight years, from ages 6-9 into their mid-teens. Researchers regularly checked in on their physical activity, screen time, sleep patterns, and eating habits. When these children reached adolescence (average age 15.8), the researchers assessed their mental health using standardized measures of stress and depression.
The data painted a clear picture: teenagers who had accumulated more total screen time and mobile device use throughout childhood showed significantly higher levels of stress and depressive symptoms. [...]
Physical activity told the opposite story. Teens who maintained higher activity levels during childhood...showed better mental health outcomes. This protective effect remained significant even after researchers accounted for factors like parental education, body composition, and puberty status. [...] Surprisingly, neither diet quality nor sleep duration showed strong relationships with teen mental health in this study.
Let's apply what you're learning in Chapter 9 to this summary.
a) This is a study that used a multiple regression design. What was the main dependent (criterion) variable?
b) Focusing on the paragraph above that starts "Physical activity told the..." what were the independent (predictor) variables? (Hint: I counted six of them if you include screen time).
c) Mock up a little regression table. putting the criterion variable on the top and the predictor variables below it. Make up a beta for each predictor variable--of course you don't know what the real betas were, but you should be able to guess whether beta is positive or negative, and also to determine whether it is closer to or further from zero.
DV: xxx
IVs: beta
xxx 0.xx
xxx 0.xx
xxx 0.xx
(etc)
d) Write a "beta" sentence for two of the betas on your table. Use this template: ("There appears to be a ____ relationship between ___ and ____, such that higher levels of _____ go with higher/lower levels of _____, when controlling for ___, ____, ____, ____, and ____")
The journalist slips into causal language in this article. Here's an example:
Researchers now have more concrete evidence about lifestyle factors that might help prevent psychological distress before it takes root.