Box-and-whisker plots of General Cognitive Ability scores (DAS-II), Language scores (OWLS) and Executive Function scores (DAS-II and NEPSY-II). All test Z-scores are adjusted to population norms. Key: darker gray is boys and lighter gray is girls. The central line in the box indicates the median (50th centile), while the top of the box indicates the 75th centile and the bottom of the box indicates the 25th centile. If ELGANs had the expected normal distribution of term-born children, the middle of the box would be at Z=0 and the upper and lower ends of the box would be at Z=1 and Z= −1, respectively. V=Verbal Reasoning (DAS-II), NV=Nonverbal Reasoning (DAS-II), LC=Listening Comprehension (OWLS), OE=Oral Expression (OWLS), WM=Working Memory (DAS-II), AA=Auditory Attention (NEPSY-II), RS=Auditory Response Set (NEPSY-II), INI=Inhibition Inhibition (NEPSY-II), INS=Inhibition Switching (NEPSY-II), AS=Animal Sorting (NEPSY-II). Maximum N=874.