sentences:  A significantly positive and fairly substantial effects was found on increasing the probability of attending school and of passing the first grade, increasing the grade attained by age 13, increasing completed schooling attainment, and for adults aged 25–40 increasing IQ test scores.31% of children under the age of 5 in the developing world are moderately (height-for-age is below minus 2 standard deviations) or severely stunted (below minus 3 standard deviations).The prevalence was even higher previously since the worldwide prevalence of stunting is declining by about half of a percentage point each year.