LAUSR

We compare the results of the Standard Progressive Matrices on two samples from Khartoum, one from 1999 (N 6877) and the other from 2010 (N 5659), both aged between 9 and 25. We show that in 7 out of 12 age groups there has been a significant Negative Flynn Effect over this period. Among those aged 9 to 18 - directly comparable as they are population samples - we found a significant aggregate loss of 2.13 IQ points between 1999 and 2010 comparing these two groups. The sample, in part, is elite and we note that a cessation of the Flynn Effect has also been reported in an elite Brazilian sample; another developing country. We examine a number of factors which may be behind our finding, in particular changes in the Sudanese education system, changes in the Khartoum population, and dysgenic fertility in Sudan.