Moving young children from the Third World to Sweden wipes out about half of their national IQ deficit.  What about performance in high school?  Vinnerljung et al.’s “School Performance at Age 16 Among International Adoptees” (International Social Work, 2010)  compiles the numbers, once again breaking them down by regular Swedes, Korean adoptees, and non-Korean adoptees.  Since these are high school students rather than conscripts, the data include women, yielding a much larger sample.  But otherwise, the national origin of the adoptees is basically the same as in Dalen et al. (2008) and Odenstad et al. (2008).  India, Thailand, Chile, Sri Lanka, Colombia, Ethiopia, and Ecuador top the list.

To start, imagine growing up in Sweden had zero effect on high school performance.  How would the non-Korean adoptees do?  As discussed earlier, if the non-Koreans had average IQ for their home countries, their mean IQ would be 84.  On the international PISA tests of science, reading, and math, countries with IQs around 84 score about one standard deviation below Sweden.*

When you look at adoptees’ actual grades, however, the performance gap is much smaller.  Combining males and females, non-Koreans have an average GPA of 2.95, versus 3.24 for regular Swedes.  It’s not in the paper, but Vinnerljung emailed me the standard deviation: .78.  That’s a performance gap of only .37 SDs – over 60% less than you would expect from the PISA scores.  The gap is even smaller for non-Koreans who were adopted as infants.  And as I emphasized in my previous post, we should expect the international adoptees to be below average for their home countries, so the grade gain of growing up Swedish is probably even greater than it looks. 

What about the Korean adoptees?  They once again do better than regular Swedes, with an average GPA of 3.42.**  That’s an edge of .24 SDs – almost exactly the PISA gap between Sweden and Korea.

For grades, like IQ, there are two stories to weave.  The pessimist can say, “Even in Sweden, non-Koreans’ performance in school is well below average.”  The optimist can say, “Non-Koreans in Sweden do much better than they would have done back home.”  While both stories are correct, the latter is far more insightful.  The fact that non-Koreans underperform in Swedish schools is obvious at a glance.  The fact that non-Koreans excel compared to the relevant counter-factual, in contrast, is easy to miss.  Wherever you’re from, Sweden is a good place to learn.

* The PISA gap is roughly 100 points, and scores are normed to have a standard deviation of 100.

** This slightly overstates Korean performance, because the Korean
adoptees are over two-thirds female, and girls in all groups have higher
GPAs than boys.  If you separately compare genders, Korean boys are .18 SDs and Korean girls are .18 SDs above the mixed-gender Swedish average.