Does intelligence have nonlinear effects on political opinions?

<p style="line-height:1.38"><span style="font-size:11pt; font-variant:normal; white-space:pre-wrap"><span style="font-family:Arial,sans-serif"><span style="color:#000000"><span style="font-weight:400"><span style="font-style:normal"><span style="text-decoration:none">We sought to study intelligence&rsquo;s relationship with political opinions with particular interest in nonlinear associations. We surveyed 1,003 American adults using Prolific, where we measured English vocabulary ability, as well as 26 political opinions. We find that intelligence has detectable linear associations with most political opinions (21 of 26). Using natural splines and the multivariate adaptive regression splines (MARS) algorithm, we find evidence of nonlinear effects on both individual opinions (15 of 26) and a general conservatism score. Specifically, the association between intelligence and conservatism is mainly negative, but becomes positive in the right tail.</span></span></span></span></span></span>