Smart fraction theory supposes that gifted and talented persons are especially relevant for societal development. Using results for the 95th percentile from TIMSS 1995- 2007, PISA 2000-2006 and PIRLS 2001-2006 we calculated an ability sum value (N=90 countries) for the upper level group (equivalent to a within country IQ-threshold of 125 or a student assessment score of 667) and compared its influence with the mean ability and the 5th percentile ability on wealth (GDP), patent rates, Nobel Prizes, numbers of scientists, political variables (government effectiveness, democracy, rule of law, political liberty), HIV, AIDS and homicide. Additionally, using information on school and professional education, we estimated the cognitive competence of political leaders in N=90 countries. Results of correlations, regression and path analyses generally show a larger impact of the smart fractions’ ability on positively valued outcomes than of the mean result or the 5th percentile fraction. The influence of the 5th percentile fraction on HIV, AIDS and homicide, however, was stronger. The intelligence of politicians was less important, a longitudinal crosslagged analysis could show a positive influence on the cognitive development of nations.