Medical and scientific discoveries, inventions, new technologies and environmental problems meet with a relatively high interest among the citizens of Europe, the United State and Canada, and a more limited interest in Japan, reflecting different cultural and political concerns. People’s understanding of scientific concepts in these four areas is, however, relatively low. Around 10% of adults in the United States and 20% of those in the other three zones are well informed. This study examines the capacity of the population to understand the reasoning used in the most important scientific and technological questions, and suggests there is a need to improve education. Public opinion is also essential if new uses are to be developed for sensitive materials.