Accountability: a social magnifier of the dilution effect.

This research demonstrated that accountability can not only reduce judgmental bias, but also exacerbate it--in this case, the dilution effect. Ss made predictions from either diagnostic information alone or diagnostic information plus mixtures of additional data (nondiagnostic information, additional diagnostic data pointing to either the same conclusion or the opposite conclusion). Relative to unaccountable Ss, accountable Ss (a) diluted their predictions in response to nondiagnostic information and (b) were more responsive to additional diagnostic information. The accountability manipulation motivated subjects to use a wide range of information in making judgments, but did not make them more discriminating judges of the usefulness of that information.