Core Studies| Cognitive Psychology| Loftus and Palmer (1947): Reconstruction of auto mobile destruction: An example of interaction between language and memory

A bit  of background information

Elizabeth Loftus

Loftus and Palmer were primarily interested in researching how language and more so how the verbs in leading questions effected our memory, Such a study would be beneficial to the police force in their interviewing training.

Aim

 The aim of their study was to observe if the nature of a question had an effect of the answer given (leading questions); but more specifically how changing the verb in the sentence effected speed estimates,

Methodology

Loftus and Palmer created two separate laboratory experiments; which allowed them to maintain a high degree of control however with the nature if this experiment you can expect there to be a low ecological validity ( blog post on it is here).

Experiment 1

The participants consisted of 45 students randomly split into 5 groups. These stuident watched 7 film clips of traffic accidents ( which were obtained from a Seattle safety agency). Each of the clips varied in length of between 5-30 seconds. After viewing each of the film clips, they were given a questionnaire. This questionnaire consisted of 2 questions, the first one asking participants to describe what they have just seen and secondly the critical question (now, the critical question had a different verb for each one of the groups)

Group 1: About how fast were the cars going when they smashed into each other?

Group 2: About how fast were the cars going when they collided with each other?

Group 3: About how fast were the cars going when they bumped each other?

Group 4: About how fast were the cars going when they hit each other?

Group 5: About how fast were the cars going when they contacted with each other?

IMPORTANT: PARTICIPANTS DID NOT KNOW LOFTUS AND PALMER CHANGED THE VERB IN THE CRITICAL QUESTION, APART FROM THAT ALL PARTICIPANTS HAD BEEN SHOWN THE SAME 7 FILM CLIPS AND THE SAME QUESTION WAS ASKED APART FROM THE CRITICAL QUESTION,

Changing the verb in fact was the Independent Variable, there fore any differences in the results would be due to this very change

Findings

Loftus and Palmer predicted that with the higher intensity of the verb the higher the estimate and their results did present that same idea,

Estimated Speeds By Verb in mph (miles per hour)

Smashed     = 40.8 
Collided      = 39.3
Bumped      = 38.1
Hit               = 34.0
Contacted   = 31.8

It is therefore clear that by these results L&P ( Loftus and Palmer) were able to distort the memories of participants by using clear explanations for two reasons.

•  L&P were able to distort the memories of the participants as the information received after the event had become a part  of the memory
• Or the fact that the memory wasn't distorted or influenced by the verb at all it was actually due to  demand characteristics ( what the researchers wanted to know)

Experiment 2

Experiment 2 was based upon experiment 1 although it was different in the way it was carried out. It was basically used to provide additional information about the origin of the estimates,

Methodology 

A 150 students were used this time which is a very much bigger sample than in the first experiment, these students were asked to view a 1 min long video which contained a 4 sec, scene of a multiple car accident, and were then asked about it.

This time 3 conditions were used and the IV is the same as the last experiment where by the verb is manipulated,

50 participants were asked: How fast  were the cars going when they hit each other?
50 participants were asked: How fast were the cars going when they smashed into each other?
50 participants were the control group and weren't asked anything regarding the speed of the cars.

A week post the experiments the participants returned and were asked without watching the film again, a series of questions. This time the critical question was 'Did you see any broken glass?' this question was a part of longer questions which were placed in a random position on each participants question paper, The participants weren't aware that there actually wasn't any glass in the film. 

Results

Did you see any smashed glass?

Response                          Smashed                            Hit                                  Control

YES                                      16                                    7                                         6

NO                                        34                                   43                                       44

The  results have shown that the verb did have a miss-perception of glass in the film, In fact the participants in the smashed group were twice as likely to recall seeing broken glass

Explanation Of Results

L&P came up with a Reconstructive Hypothesis as an Explanation of the results for the second experiment,

They Argue that we have 2 types of information going to our memories in any type of event, these are :

Firstly perceiving the event which we were in (in the L&P study this is witnessing the video of a car crash), The second type is the other information obtained after the event (the hit and smash groups,)

Overtime these two pieces of information will become unified in a way in which it will be hard to establish from which source the specific detail came from, as we all just have one memory. In the case of L&P participants first were asked questions about what they have witnessed in the video, then by asking About How fast were the cars going when they smashed into each other? the experimenters were giving participants extra information, by saying that the cars smashed into each other  there for witnessing the car crash and then the fact that the cars smashed into each-other unified this information,and the memory of the car crash was more severe, thus participants in the smashed condition were more likely to to say that the broken glass was present in the scene.

Evaluation

Contribution to Psychology:

Loftus's Devlin Report in 1976 has meant that the trial judge is required to instruct the jury that it is not safe to convict on a single eye witness testimony, except in exceptional circumstances or when substantial corroborative evidence is present,However some psychologists argue that whilst loftus' research has proven beneficial to the judiciary and police system with the re constructive hypothesis has meant that police and lawyers are urged to use as few leading questions as possible, this is still widely carried out regardless of the research, Additionally, Some psychologists also suggest that it is not purely the type of question that is asked it is also many other factors involved, these include: food, alcohol, emotions, the environment you were in, what the event meant to you , who you were with etc.

Method:

Everyone saw the same films regardless of the questions asked, By using a Lab Experiment has meant that a high level of control was easily obtainable which allowed the researches to separate the IV from the DV and see if it is only the IV that was effecting the DV. Overall the researchers had control over everything inc. :age of participants, the videos shown and locations of experiment. Participants also had the same questions apart from the model conditions and critical q. in experiment 1.However participants were often looking for clues from researchers from how to behave or hoe a response which created demand characteristics, thus outcome of the experiment could have been influential on the outcome of the experiment, Some psychologist suggest that the witnesses merely followed the questionnaire leaving the original memory intact for retrieval under appropriate conditions. Also when witnessing events in real life we often have some involvement with the people or the action therefore it should be difficult to generalise findings.

Participants:

The sample of participants was fairly large especially in the second experiment, which allowed the results to be implied to the group of participants in the research (Students).However students are very different from the general public as they are used to remembering useless information and are usually better at memory test from having to do them at college/ university and generally having a better memory capacity. They are also likely to be inexperienced drivers. This has meant that any data collected is not able to be generalised to the rest of the public.

Type of Data Collected:

Qualitative data was collected which is useful for making statistical analysis. However we didnt have any motive for giving qualitative data and we are unsure of how confident the participants were with their estimates which would therefore produce invalid data; as a way to combat this from occuring again participants could put in a rating scale style question which would allow participants to give the confidence rating,

Ethics:

No ethical guidelines were broken as participants gave informed consent and they were in a controlled environment. However participants could potentially have been caused distress through viewing the car crash clips as it is not particularly pleasant to watch , additionally participants may have been a part of a car accident or someone they new could have been a victim of or a part of one which in this case it could be found to be particularly distressing to participants,

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This is revision material for the OCR course of AS Psychology . This content has been created with the help of the revision website at : http://www.holah.co.uk as well as booklets created by teachers at my school for use in lessons.