Group 1 were asked questions which were entirely consistent with the original film, in contrast to group 2 who were given the same questions except one which was changed to a question which conflicted with the original witnessed event. After one week, all of the participants were asked a further ten questions, and for the final question it was a conflicting question.
Loftus found that only 2.7 per cent of the participants in group 1 gave the incorrect answer. Loftus also found that 17.3 per cent of group 2 also answered incorrect.
Therefore, Loftus concluded that for group 2, the non-existent image which was repeatedly asked about in the conflicting question, it had been added to the original memory representation of the event at the question stage so that it was now recalled as being part of the original event.
There are other factors apart from misleading questions that affect eye witness testimony. Loftus reported a study in 1979 about the anxiety of the witness, where participants were exposed to one of the two situations stated below:
- Overhearing a low-key discussion in a laboratory about an equipment failure. A person then emerged from the laboratory holding a pen and with grease on his hands.
- Overhearing a heated and hostile discussion in a laboratory. After the sound of breaking glass and crashing chairs a man emerged from the laboratory holding a paper knife covered in blood.
The participants were then given 50 photos and asked to identify the person who came out of the laboratory. It was found that the first group of participants accurately identified the man holding the pen about 49 per cent of the time. Whereas the second group of participants that had witnessed the man with the bloodstained knife were only successful at identifying him 33 per cent of the time.
These findings became known as ‘weapon focus’, whereby the witness concentrates on the weapon. Loftus concluded that the anxiety induced by the sight of a weapon narrows the focus of attention.
Another factor that affects eye witness testimony is the method of testing the witness. Loftus often used forced – choice tests, however this may have given a false picture. Korait and Goldsmith have shown that witness accuracy can be dramatically increased if tests do not rely on forced- choice format and if witnesses are allowed to not answer if they feel unsure of the answer.
It is clear from Loftus’s research that memory for events can be fundamentally altered in the light of misleading post-event information. However, Loftus’s studies have been criticized for artificiality. It is difficult to reproduce such conditions in the laboratory for ethical reasons. Furthermore it is possible that eye witnesses remember real events differently then they remember staged events.
Loftus has also been criticized for her method of testing recall, as people are more accurate if asked questions in a logical order and not if they are forced to answer if they are unsure about the answer.