Underachievement at school relative to potential: links between reasoning, phonological decoding, short-term memory, and complex grammar

Around 6% of U.K. children are underachieving at school relative to their potential (URP). We explored whether difficulties with phonological decoding, short-term memory (STM), and complex grammar may be responsible. We compared school-based reading test data or formal SATs, and verbal reasoning in 2462 children (150 URP and 2312 non-URP children) and administered a 7-min follow-up test to a matched subgroup of 106 URP and 106 non-URP children. Thirty-three of our original 150 URP children (22%) scored in the top 10% nationally for verbal reasoning, compared with 46 of our 2312 non-URP children (2%). Phonological decoding, STM, and complex grammar acquisition made independent URP contributions in children aged 7-9; in ages 10-12, only phonological decoding contributed. URP children were more likely to show multiple difficulties. The 7-min test enables school staff to quickly identify areas for targeted support. Some URP children not previously detected as capable may be encouraged to take up and succeed in further education.