J. Biosoc. Sci., (2015) 47, 281–310, 6 Cambridge University Press, 2014 doi:10.1017/S0021932014000066 First published online 6 Mar 2014 COGNITIVE ABILITY OF PRESCHOOL, PRIMARY AND SECONDARY SCHOOL CHILDREN IN COSTA RICA HEINER RINDERMANN* 1 , EVA-MARIA STIEGMAIER† and GERHARD MEISENBERG‡ *Department of Psychology, Chemnitz University of Technology, Germany, †Clinical and Health Psychologist, Zeltweg, Austria and ‡Ross University Medical School, Dominica Summary. Cognitive abilities of children in Costa Rica and Austria were com- pared using three age groups (N ¼ 385/366). Cognitive ability tests (mental speed, culture reduced/fluid intelligence, literacy/crystallized intelligence) were applied that differed in the extent to which they refer to school-related knowl- edge. Preschool children (kindergarten, 5–6 years old, N CR ¼ 80, N Au ¼ 51) were assessed with the Coloured Progressive Matrices (CPM), primary school children (4th grade, 9–11 years old, N CR ¼ 71, N Au ¼ 71) with ZVT (a trail- making test), Standard Progressive Matrices (SPM) and items from PIRLS- Reading and TIMSS-Mathematics, and secondary school students (15–16 years old, N CR ¼ 48, N Au ¼ 48) with ZVT, Advanced Progressive Matrices (APM) and items from PISA-Reading and PISA-Mathematics. Additionally, parents and pupils were given questionnaires covering family characteristics and in- struction. Average cognitive abilities were higher in Austria (Greenwich-IQ M CR ¼ 87 and M Au ¼ 99, d IQ ¼ 12 points) and differences were smaller in pre- school than in secondary school (d IQ ¼ 7 vs 20 points). Differences in crystal- lized intelligence were larger than in fluid intelligence (mental speed: d IQ ¼ 12, Raven: d IQ ¼ 10, student achievement tests: d IQ ¼ 17 IQ points). Differences were larger in comparisons at the level of g-factors. Austrian children were also taller (6.80 cm, d ¼ 1.07 SD), but had lower body mass index (BMI CR ¼ 19.35 vs BMI Au ¼ 17.59, d ¼0.89 SD). Different causal hypotheses explaining these differences are compared. Introduction Latin American countries have participated in several international (Programme for International Student Assessment/PISA, Trends in International Mathematics and Science Study/TIMSS, Progress in International Reading Literacy Study/PIRLS) and 281 1 Corresponding author. Email: heiner.rindermann@psychologie.tu-chemnitz.de