How individuals process information on nanotechnology risks is critically dependent on the perceived cultural values of the information source. The impact of this "cultural credibility heuristic," experimental data show, can either accentuate or mitigate cultural polarization with respect to nanotechnology risk perceptions.
We present the results from the second in a series of ongoing experimental studies of public perceptions of nanotechnology risks. Like the first study, the current one found that members of the public, most of whom know little or nothing about nanotechnology, polarize along cultural lines when exposed to information about it. Extending previous results, the current study also found that cultural polarization of this sort interacts with the perceived cultural identities of policy advocates. Polarization along expected lines grew even more extreme when subjects of diverse cultural outlooks observed an advocate whose values they share advancing an argument they were predisposed to accept, and an advocate whose values they reject advancing an argument they were predisposed to resist. But when those same advocates were assigned the opposite positions, subjects formed perceptions of nanotechnology risks diametrically opposed to the ones normally associated with their own cultural predispositions. Finally, when there was no consistent relationship between the perceived values of advocates and positions taken on nanotechnology risk and benefits, cultural polarization was neutralized. The significance of these findings for promotion of informed public understanding of nanotechnology is discussed.