This research offers one of the first analyses of the US public's views about synthetic biology, based on nationally representative survey data. We provide in-depth, multiyear descriptive results of public attitudes toward this issue and compare them with individuals’ attitudes toward other issues. Our data indicate that the public does not generally feel informed about synthetic biology or believe it is personally important. However, Americans express more reservations about the moral downside of synthetic biology than about other issues. Multivariate analysis reveals that values and predispositions—particularly religiosity, deference to scientific authority and trust in scientists—are linked to support for synthetic biology. We also see evidence indicating that deference to scientific authority reduces the potential for religiosity and distrust in scientists to polarize public attitudes about synthetic biology. We conclude by describing the implications of our findings for the development of synthetic biology research and upstream public engagement.