The paper discusses the emergence of meritocratic traditions through twentieth century transnational exchanges of theories, methods and techniques for measuring merit. An initial continental European examination tradition marked by process control and dominated by expert judgments in the hands of teacher was contested by the new psychometric techniques developed by American measurement experts and adopted by several other countries. The paper addresses how transatlantic research projects from the 1930s to the 1960s constructed different premises of policy legitimation, which can be seen as one explanation to why new approaches to measuring merit gained legitimacy in countries such Sweden and the Netherlands whereas Norway, Denmark and Germany rejected the American influence and sustain the examination tradition to date.