Thinking outside the red box: Does the simultaneous Showup distinguish between filler siphoning and diagnostic feature detection accounts of lineup/Showup differences?

Lineups are considered a superior method of identification to showups, but why is contested. There are two main theories: diagnostic feature detection theory, which holds that surrounding the suspect with fillers causes the eyewitness to focus on the features that are most diagnostic, and differential filler siphoning theory that claims that the fillers draw incorrect choices away from the suspect. Colloff and Wixted (2020) created a novel identification task, called a simultaneous showup, designed to prevent filler siphoning, while still allowing comparison to occur between members of the array.

Estimator variables can matter even for high-confidence lineup identifications made under pristine conditions.

Objective: According to the pristine conditions hypothesis, high-confidence identifications will be "remarkably accurate" when identification procedures (i.e., system variables, e.