Reading focus
Syllabus: Where Do Individual Differences Come From?
Separate the randomized care comparison from the comparison with never-institutionalized children, the placement-age analysis, and the study’s ethical questions.
Why you’re reading it. Finish with an environmental intervention whose causal scope can be stated precisely.
A question to consider. What would this intervention justify saying about the effect of improved care, and why would it not explain all initial differences among children or predict the effect of ordinary household differences between the fictional siblings?
Why this reading
Developmental differences can reflect both prior experience and selection into environments. This study uses randomized foster-care placement to examine cognitive development following early institutional care. It gives the reader a concrete way to distinguish an intervention comparison from a claim about why children initially differed.
Before you read
Distinguish random assignment from a representative sample. An intention-to-treat comparison follows assignment even when subsequent care changes. A comparison with children never institutionalized answers a different question from the randomized comparison.
Read for
- Identify which groups were formed by random assignment and which were comparison groups.
- Track the cognitive assessments over time and ask what each comparison estimates.
- Separate the placement effect from the interpretation of age-at-placement differences.
- Examine the ethical responsibilities created by a study involving children already living in institutions.
Consider afterwards
- What would make the age pattern evidence for a sensitive period rather than simply a longer exposure to foster care?
- Which parts of the intervention would have to be reproduced before expecting similar results elsewhere?
Editorial context
The reported benefits concern this intervention, population, and follow-up period. They do not establish a universal developmental deadline or identify a single caregiving mechanism. Randomizing an offer of alternative care is also different from randomly assigning children to early deprivation. Read the study's procedures and ethical account alongside its outcomes; a persuasive causal comparison does not by itself settle those ethical questions.