A new study concludes that children who spend more time reading physical books tend to have better concentration skills than those who primarily read on digital devices. The researchers suggest this is because physical books offer fewer distractions. Which of the following, if true, would most seriously weaken the researchers' suggested reason for the difference in concentration skills?
- AThe study was conducted only with children aged 8-10, who may be less familiar with digital devices.
- BMany digital reading platforms now offer 'focus modes' that minimize distractions.
- CChildren who are already predisposed to better concentration skills are more likely to choose reading physical books.
- DParents who encourage reading physical books often also limit screen time for other activities.
Show answer & explanationAnswer & explanation
Correct answer: C. Children who are already predisposed to better concentration skills are more likely to choose reading physical books.
The researchers suggest that physical books offer 'fewer distractions' as the reason for better concentration. Option B introduces an alternative explanation: self-selection bias. If children with *pre-existing* better concentration skills are more likely to choose physical books, then their concentration skills are not necessarily *developed* by physical books or due to fewer distractions, but rather are a pre-existing characteristic of the group that chooses physical books. This weakens the researchers' suggested causal reason.
Why the other options are wrong
- A. This challenges the generalizability of the study but doesn't directly weaken the *suggested reason* (fewer distractions) for the observed difference.
- B. While digital platforms *can* minimize distractions, this doesn't mean the children in the study *used* these features or that physical books *don't* inherently offer fewer distractions.
- D. This introduces another confounding variable (limited screen time), which could contribute to better concentration, but doesn't directly weaken the idea that physical books *themselves* offer fewer distractions and thus contribute to concentration during reading.
Weakening Specific Causal Mechanisms
To weaken a specific reason given for an observed effect, introduce an alternative explanation for the effect that is more plausible or equally plausible.
- Focus on the 'why' or 'how' aspect of the claim.
- Look for confounding variables or reverse causation.
- The alternative explanation must directly compete with the proposed reason.
Memory trick: The magician's trick: it wasn't the wand, it was the hidden string!