Conservatives and liberals have similar physiological responses to threats.

About a decade ago, a study documented that conservatives have stronger physiological responses to threatening stimuli than liberals. This work launched an approach aimed at uncovering the biological roots of ideology. Despite wide-ranging scientific and popular impact, independent laboratories have not replicated the study. We conducted a pre-registered direct replication (n = 202) and conceptual replications in the United States (n = 352) and the Netherlands (n = 81). Our analyses do not support the conclusions of the original study, nor do we find evidence for broader claims regarding the effect of disgust and the existence of a physiological trait. Rather than studying unconscious responses as the real predispositions, alignment between conscious and unconscious responses promises deeper insights into the emotional roots of ideology.