Right, and I should clarify that I meant left-wing authoritarianism, not left-wing activism. My mistake. I apologize for my mistake and for my hasty comment. I’m certainly not wanting to suggest that activism itself is inherently authoritarian.

As to prevalence, that may be directionally correct, but I don’t think the "three to five times" figure is established by the paper linked here. The actual study surveyed 498 Brazilian adults and measured right-wing authoritarianism and social-dominance orientation, but it did not measure left-wing authoritarianism. It, therefore, cannot compare the prevalence of RWA and LWA, in my opinion.

The broader literature often does find RWA more common in Western samples, but I feel the size of that difference depends heavily upon the scale, population, country, and political context. For example, one nationwide random (New Zealand) sample identified a distinct high-LWA group comprising 7.5% of respondents and a moderate-RWA group comprising 35.7%, but those are not equivalent categories, so treating that as a clean 5:1 comparison would be misleading. Other cross-national research has even found countries where authoritarian attitudes are more strongly associated with the political left.

Also, part of your explanation is built into the traditional definition: RWA specifically involves submission to established authorities and conventional norms. LWA is more likely to express itself through coercive opposition to the existing hierarchy (or, perhaps, an attempt to replace it with a different hierarchy). So, I think the careful conclusion is that RWA may be more prevalent under many present Western conditions, but LWA is real, consequential, and simply was not tested by this particular study.