ABSTRACT
The U.S. Supreme Court has outlined five criteria on which evaluations of eyewitness identifications should be based (certainty, view, attention, description, and time; Neil v. Biggers, 1972). We postulated that certainty plays a qualitatively different role from the four other Biggers criteria in evaluations of eyewitness identification testimony. Specifically, we hypothesized that participants would ignore reports on other criteria when certainty was high (the certainty-trumps hypothesis), but not when certainty was low. Participants (N = 386) read a fictitious trial transcript in which three of the five Biggers criteria were manipulated (certainty, view, and attention, or certainty, description, and time) and completed a questionnaire. The certainty-trumps hypothesis was not supported. Instead, the Biggers criteria combined only as main effects, not interactions, supporting a summative hypothesis. Surprisingly, collateral effects indicated that manipulations of one criterion (e.g., certainty) affected perceptions of other criteria (e.g., attention and view) and vice versa. Implications of the results are discussed.
