Factors affecting eyewitness testimony: Misleading information

eyewitness testimony

The ability of people to remember the details of events, such as accidents and crimes, which they themselves have observed. Accuracy of EWT can be affected by factors such as misleading information, leading questions and anxiety 

Loftus and Palmer (1974)

conducted a study on the effects of leading questions on eyewitness testimony.

Procedure: Asked five groups of participants to watch a clip of a car crash and then gave them this question “About how fast were the cars going when they ________”. Each group was given a different verb which suggested a speed at which the car was going.

Findings:Participants estimated that the speed was higher for verbs like “smashed” (40.5mph) than for “contacted” (31.8mph)

conclusions: Loftus and Palmer suggest two explanations for why leading questions affect EWT:

1.Response Bias: The different speed estimates occurred because the participants gave the answer they thought the researcher wanted – the critical word (e.g. ‘smashed’ or ‘hit’) influenced or biased the participants response.

2.Substitution Explanation: The results could be due to the critical word changing/distorting the participants memory so they actually ‘see’ the accident differently, i.e. more or less severe (memory is altered).

Gabbert et al. (2003)

found that it does because witnesses combine misinformation from other witnesses with their own memories.

Bartlett (1932)

•stated that memory doesn’t replicate events exactly as they happened.

•Instead, we reconstruct events based on prior experiences and expectations, or schemas.

Schemas help us fill in the gaps in our knowledge and simplify processing of information.

 They can lead to memory distortions when new information doesn’t readily fit into our existing schema.

 Cultural expectations or stereotypes also influence schemas

Tuckey and Brewer (2003)

•Tuckey and Brewer found that most people’s bank robbery schema include the following:

-Bank robbers are male

-They wear some kind of disguise

-They wear dark clothes

-They demand money from cashiers

-They have a getaway car waiting with a driver in it

•They showed people a video of a staged hold-up and found what Bartlett would expect…

•…That people tended to remember these elements of the film better than others

leading questions

questions that lead witnesses to alter their memory for events

post-event discussions

when people talk about what they have witnessed - contaminate their memory for the event