“Yes, I Have Sometimes Stolen Bikes”: Blindness for Norm‐Violating Behaviors and Implications for Suspect Interrogations

Abstract

Across two experiments, we studied a phenomenon akin to choice blindness in the context of participants' accounts of their own history of norm-violating behaviors. In Experiment 1, N = 67 participants filled in an 18-item questionnaire about their history of norm-violating behaviors (QHNVB). Subsequently, they were questioned about four of their answers, two of which had covertly been manipulated by the experimenter. Of the 134 manipulations, 20 (14.9%) remained undetected concurrently and 13 were accepted in retrospect (9.7%). In Experiment 2 (N = 37), we inserted a one-week interval between questionnaire and interview. Twenty-seven (36.5%) of the 74 manipulations remained undetected concurrently and three were accepted in retrospect (8.1%). Data obtained in a four-week follow-up indicated that our manipulations may have long-term effects on participants' perception of their own history of norm-violating behaviors. Implications for the occurrence of false confessions during the course of an interrogation are discussed.

Memory impairment is not sufficient for choice blindness to occur

“…Furthermore, participants indicated how confident they were that this corresponded with their original rating on an 11-point scale ranging from 0 to 100%. Subsequently, as in previous studies (e.g., Johansson et al, 2005; Hall et al, 2010; Sauerland et al, 2013a, b), participants received a questionnaire to determine whether they had detected the manipulations before we disclosed that information, but refrained from revealing it while performing the task. Given that many participants were confused by the structure of the questionnaire 1 , it is doubtful whether the trials reported in the post-test questionnaire reflect genuine detections.…”

“…Previous studies have successfully ruled out a number of possible explanations, including poor encoding of the original (Johansson et al, 2005) or manipulated stimuli (Sauerland et al, 2013a), compliance (Johansson et al, 2005, 2008; Sauerland et al, 2013a), suggestibility or the tendency to react in socially desirable ways (Merckelbach et al, 2011; Sauerland et al, 2013a, b). However, none of these studies specifically aimed at tackling the cognitive mechanisms underlying the phenomenon.…”

“…The observation that blindness phenomena can be obtained even when the manipulated outcome is presented minutes after the original choice (Johansson et al, 2005; Hall et al, 2012) supports this position. Moreover, choice blindness may occur for stimuli of personal and moral significance (Hall et al, 2013; Sauerland et al, 2013b), again suggesting that memory decay may not be the sole mechanism driving the effect.…”

“…This is a valid concern, as we have no means of knowing whether participants indeed recalled or reevaluated. However, recent findings indicate that choice blindness manipulations can shape preferences in favor of the manipulated outcome in a second round of choices (i.e., reevaluation; Johansson et al, 2008, 2013; Sauerland et al, 2013b). Importantly, such a shift was evident for both blind participants and detectors.…”

Memory blindness: Altered memory reports lead to distortion in eyewitness memory

“…Although some variables, like the type of decision, the manner in which the manipulation occurs, and other between-experiment variables, seem to produce different rates of blindness, choice blindness has been shown to be robust across a variety of domains. Participants' blindness rates have been remarkably high in studies of their political and moral attitudes (53 %; Hall, Johansson, & Strandberg, 2012), financial decision making (63 %;McLaughlin & Somerville, 2013), and even their reported histories of criminal and norm-violating behavior (8 %-10 %; Sauerland et al, 2013).…”