To assess intelligence, a short version of Cattell's Cultural Fair Test (CFT 20 R; Weiß, 2006) was applied. The children were required to solve four timed paper-and-pencil subscales with 11 to 15 items each and a total of 56 items.2 Reliabilities for the single tasks ranged from rtt = .47 to rtt = .67. For the CFT sum score, a split-half reliability of rtt = .78 was found (Spearman–Brown corrected).