“…In England boys are more likely to be identified with special educational needs, and are over-represented in specialist schools relative to girls (National Statistics, 2007). Parent reports indicate an increased risk of inattentive behaviour for twins compared to their singleton siblings (Levy, McLaughlin, Wood, Hay, & Waldman, 1996), and so being male as well as being a twin may act as a 'double disadvantage' on a population level, in terms of cognitive and/or educational performance (Hay & Preedy, 2006). While our sample's cognitive performance is consistent with normative data, the marginally higher academic achievement of the cohort compared to national statistics for 2004, could indicate an absence of the lowest academic achievers.…”