The confidence people have in what they remember having seen is affected by their awareness of what other people claim to have seen. The accuracy of an eyewitness account is doubtful if the eyewitness contradicts what other eyewitnesses claim to have seen. If several eyewitnesses all identify the same suspect in a lineup, it is more likely that the suspect committed the crime than if only one eyewitness identifies the suspect. Police officers are more interested in the confidence witnesses have when testifying than in the accuracy of that testimony.
Studies of the reliability of eyewitness identifications show little correlation between the accuracy of a witness' s account and the confidence the witness has in the account. Certain factors can increase or undermine witness' s confidence without altering the accuracy of the identification. Ttherefore, police officers are advised to disallow suspect lineups in which witnesses can hear one another identifying suspects.
Which one of the following is a principle underlying the advice given to police officers?