An unscrupulous lawyer may gradually modify the story which his client or a witness tells by constantly adding to what is really remembered, other details so expertly contrasted with the facts, or so neatly interposed among them, that the witness gradually incorporates them in his memory and so testifies more nearly as the lawyer desires.

In our daily lives another element of contrast is also very strong--that due to social opinion.

We constantly modify our memories to agree more closely with the truths of social belief, paring down unconsciously the difference between our own and others' reports of things.

If several witnesses of an event be allowed to compare notes from time to time, they will gradually come to tell more nearly the same story.
The other curve (II) in the figure, that secured by the method of Identification, seemed to the investigators to be the most accurate.
It is not subject to the errors due to expression and to contrast, and it has the advantage of allowing the subject the right to recognise the square.

It is shown to him again, with no information that it is the same, and he decides whether from his remembrance of the earlier one, it is the same or not.