Digital SATReading and Writing: Information and IdeasHard
A team of researchers is studying the long-term effects of screen time on cognitive development in young children. They conducted a longitudinal study tracking children from birth to age seven. One finding indicates that children with more than two hours of screen time per day at age two scored, on average, 15 points lower on a standardized cognitive assessment at age five compared to children with less than 30 minutes of screen time per day. However, the study also notes that parental education levels and socioeconomic status were significantly higher in the low screen-time group. Based on this information, which of the following is the most reasonable inference regarding the relationship between screen time and cognitive development?
- ALimiting screen time to under 30 minutes per day guarantees higher cognitive scores.
- BThe observed correlation between screen time and cognitive development may be influenced by confounding variables.
- CParental education and socioeconomic status are the sole determinants of cognitive development.
- DExcessive screen time directly causes a significant reduction in cognitive ability.
Show answer & explanationAnswer & explanation
Correct answer: B. The observed correlation between screen time and cognitive development may be influenced by confounding variables.
The study presents a correlation but also highlights significant differences in parental education and socioeconomic status between the groups. These additional factors are known to influence cognitive development, suggesting they could be confounding variables that explain some or all of the observed difference, rather than screen time being the direct cause.
Why the other options are wrong
- A. The study shows an association, not a guarantee, and doesn't account for all possible variables, making this an overstatement.
- C. While important, the study does not claim these are the *sole* determinants, and other factors undoubtedly play a role, making this an overgeneralization.
- D. This is too strong a claim; the study notes other significant differences between the groups, suggesting causation isn't definitively established.
Confounding Variable
An unmeasured third variable that influences both the independent and dependent variables, creating a spurious or misleading association.
- Can make it seem like there's a direct cause-and-effect relationship when there isn't.
- Must be considered when interpreting correlations.
- Often related to the study's design or uncontrolled factors.
Memory trick: Don't Conclude Cause, Consider Other Stuff.