[Update: I found three more sources: Program for International Student Assessment (PISA)(2009), Trends in International Mathematics and Science Study (TIMSS) (2007), and The Progress in International Reading Literacy Study (PIRLS) (2006). All three indicate the 2nd Gen Black immigrants perform substantially below 2nd Gen White immigrants and 3rd+ Gen Whites. See: Not all that… and Biracial Black-White Pisa 2009.]
In the last post, I concluded that if 2nd generation Blacks in the US had IQs no lower than 3rd+ generation Whites, the genetic racial difference between Black Africans and White Europeans could be no more than 0.6 standard deviations. This begs the question, what is the 2nd Gen Black IQ? I found 6 sources that provide hints of this Kao (2004), Masey et alia (2007), Bennet and Lutz (2009), Richwine (2009), my crack at the ADD health data, and Jason Malloy’s analysis of the GSS data.
Kao (2004) and Bennett and Lutz (2009) analyzed the national educational longitudinal study (NELS). The immigrant Black sample size was about 95. The standardized difference based on the data reported in Kao and Bennet and Lutz was .8 SD and .45 SD, respectively. The differences were statistically significant.
Massey et al. (2007) analyzed the National Longitudinal Survey of Freshmen (NLSF) and compared “native Blacks” to “Black immigrants.” They defined “Black immigrants” as “students who reported having at least one parent born abroad.” The Black immigrant N was 281. Blacks immigrants scored 111 points lower on the SAT than Whites and 57 points higher than other Blacks. The differences were statistically significant. Assuming 200 points per SD, the difference amounts to .55 SD.
Richwine (2009) analyzed the National Immigrant Survey data. He found that the children of African immigrants performed .8 SD below native Whites on backwards digit span.
Malloy analyzed the General Social Survey (GSS) data. The index of IQ used is Wordsum. Individuals that identified as “African, US born” had average measured IQs of 90 (n 1343), those identifying as “black’, foreign born” had average IQs of 88 (n 182), and those identifying as “ black, US born, parents foreign born” had IQs of 93 (n 27) . [I reanalyzed this. The second generation Black-native White gap was .6 SD (n = 82).]
I analyzed the ADD health data. The index of IQ used is picture vocabulary. Individuals identifying as Black and who indicated that their mother, father, or father and mother were not US born, had average measured IQs over .75 SD below the White mean (n 62 to 26). Individuals who identified as Black and indicated that one of their parents were born in a specific African region (Nigeria, South Africa, E/C/W Africa) had average IQs less than .2 SD below the white mean (n 10 to 16). The results were highly sensitive to the identifiers selected. [I reanalyzed this. The second generation Black-native White gap was .75 SD (n = 53).]
Best Guess. Based on the skimpy data above, the 2nd generation Black IQ is somewhere between 0.8 and 0 SD below the native White IQ. An average of the averages suggests around 0.5 SD.
Data pics and references herez