FLynn effect in Turkey: A comment on Kagitcibasi and Biricik (2011)

Kagitcibasi and Biricik (2011) presented generational IQ gains for Turkey on the Goodenough Draw-a-Man test (Draw-a-Person). Following their results (their Table 1) the mean IQ gain from 1977 to 2010 (33 years) across three different population groups was 5.24 IQ (per decade dec = 1.59 IQ points). However, Kagitcibasi and Biricik did not acknowledge the changing social composition of society: the share of groups which had a lower IQ in 1977 and 2010 decreased, and the share of groups which had a higher IQ in 1977 and 2010 increased. Considering this, we came to an estimate of dec = 3.52 IQ points for the FLynn effect in Turkey over the past decades.