At Econlib today, Bryan Caplan cites a review which highlights the differences in ways that my left-wing (elitist interventionist) friends need to consider:
[T[he observed relationship between intelligence and conservatism largely depends on how conservatism is operationalized. Social conservatism correlates with lower cognitive ability test scores, but economic conservatism correlates with higher scores (Iyer, Koleva, Graham, Ditto, & Haidt, 2012; Kemmelmeier 2008). Similarly, Feldman and Johnston (2014) find in multiple nationally representative samples that social conservatism negatively predicted educational attainment, whereas economic conservatism positively predicted educational attainment.
With such differences between the economic conservatives who tend to be classical liberals and the social conservatives, I see the old Reform party (and now the Progressive Conservatives) in Canada and the Republicans in the US as very tenuous coalitions between very different groups with very different social agendas.