The behavioural approach to Muslim politics in academic literature is a recent development. The approach emerged only in the early twenty-first century, largely as most Muslim-majority nations have been autocracies constraining the freedom of speech required to study political attitudes and behaviour. Many behaviourally driven studies have examined dimensions of Islam as predictors of political attitudes and behaviorr. These include religious affiliation, religiosity, and religious political orientation. While democracy is rare in Muslim majority nations, at the individual level, Muslim religious affiliation and religiosity only partially predict political attitudes and behaviour. Taking an expansive measure of Islamism or Islamic ideology helps us understand this, as it potentially predicts the absence of liberal democracy in Muslim countries. To do this successfully, however, more realistic external validity is required. Scholars still often define and measure Islamism differently, therefore a more standardised measure is required for comparative study.