Higher intelligence predicts stronger support for free speech. Results from 21 waves of data collection from the US General Social Survey, 1974 through 2018. New study: https://journals.sagepub.com/doi/abs/10.1177/1948550619896168 … Good summary:https://heterodoxacademy.org/social-science-freedom-of-speech/ …
Yep, I expect that both IQ and Openness predict support for free speech, and Openness might be the even stronger predictor.