Determining which countries are the smartest in the world is difficult because there are so many different factors that can be considered.
Obviously, there exist challenges to any attempt to land on a single clear-and-simple answer. Nonetheless, population and intelligence experts continue to devise new methods and approaches that bring them closer and closer to a realistic ranking of the world's smartest countries.
Some of the best-known and more widely publicized studies of world intelligence are conducted by British psychologist Richard Lynn. In a 2019 study titled The Intelligence of Nations, Lynn and collaborator David Becker measured the average IQ of citizens across 132 nations and calculated estimated scores for another 71. The top of the list looks as follows (scroll to the table at the bottom of the page for the rest).
*It would be irresponsible to neglect to mention that Lynn's studies, while arguably the most comprehensive available, often spark considerable debate. Some detractors take issue with the methods Lynn uses to compute estimates when hard data is unavailable. Others accuse Lynn, an outspoken eugenicist, of using his data to support scientifically inaccurate theories that promote white supremacist beliefs.
Education and intelligence are closely linked, as a more robust educational system tends to produce a more intelligent populace over time. With this in mind, some studies use the educational rankings of various countries as a basis for comparisons of intelligence. In 2018, the Organization for Economic Cooperation and Development (OECD) released its triennial PISA (Program for International Student Assessment) results, which compared the reading, math, and science testing scores of more than 600,000 students in 79 countries. The top 10 appear below.
Another OECD study, which used multiple data points including adult education level, chose Canada as the most intelligent nation. Japan placed second, while Israel came in third. Other high-ranking nations include Korea, the United Kingdom, the United States, Australia, and Finland.
One of the more creative studies of intelligence is the 2017 Intelligence Capital Index, or ICI, which used several factors to determine not the smartest nations overall, but which nations were most likely to leverage their smartest citizens' intelligence to "expand the frontier of knowledge and/or introduce the technologies and innovations of the knowledge economy ... Big Data, cloud computing, artificial intelligence, etc."
In the ICI study, the United States ranked number one and was the only nation to receive an A+ rating. Coming in second place was the United Kingdom, followed by Germany in third place. Other high-ranking nations on the ICI include Australia, Singapore, Sweden, Switzerland, Canada, Finland, and Denmark.
Here are the 10 countries with the highest IQs:
Japan has the world's highest IQ with an average of 106.49.