Reconstruction of automobile destruction

Reconstruction of automobile destruction was a psychological study carried out by Elizabeth Loftus and Palmer in 1974 ^[1]. The aim of the study was to investigate whether or not an eye witness's memory can be altered by information supplied to them after an event. Loftus and Palmer also wished to discover whether or not a person's memory can be influenced by this information.

Additional recommended knowledge

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Background to the study

Memory is defined as the storing, retaining and recalling of information. Prior studies have shown that memory is not always an accurate representation of our life experiences. Earlier studies have also concluded that we subconsciously try to fit memories into our current lives so we can make the memory more meaningful to us. ^[2]

Participants

Two studies were carried out by Loftus and Palmer. The first was tested on forty five students split into five categories, each with nine students. The second was carried out on one hundred and fifty students. ^[3]

Method of Study One

In the first study forty five students from the University of Washington were shown seven film clips of car accidents. The clips ranged from five to thirty seconds long. ^[4] After viewing each clip the students were asked to write a report on what they had seen. They were asked a series of questions about the videos. The critical question in this study was "At what speed was the car travelling?" The five categories of students were asked this question but with a different verb (shown below). Loftus and Palmer wanted to see if the verb influenced the students (eye witnesses') answers.

1) About how fast were the cars going when they collided with each other?

2) About how fast were the cars going when they smashed into each other?

3) About how fast were the cars going when they bumped into each other?

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

5) About how fast were the cars going when they contacted each other? ^[5]

Results of Study One

Loftus and Palmer found that the more intense the verb used in the question, the higher the estimate of speed. The actual results were:

Smashed : 40.8 miles per hour

Collided : 39.3 miles per hour

Bumped: 38.1 miles per hour

Hit : 34 miles per hour

Contacted : 31.8 miles per hour ^[6]

Loftus and Palmer explained that the more severe the verb the more likely we are to estimate a higher speed. However they also argued that the findings could simply be due to a distorted memory caused by the verb that was used. They stated that some answers may have been due to a response bias meaning people who could not remember simply devised a made up answer.

Method of Study Two

In the second study, one hundred and fifty students watched a one minute video clip which contained a four second scene of a multiple car pile-up. They were then asked a series of questions about the scene. The same question ("about how fast were the cars going...") was used but another critical question was asked: "Was there any broken glass at the scene?". In this study there were three groups of students. Each group was asked a different version of the question concerning the speed of the automobiles. One group was asked "About how fast were the cars going then they smashed into each other?", the second was asked "About what speed were the cars going when they hit each other?" and finally the last group were not asked the question about speed.

Results of Study Two

In study two Loftus and Palmer discovered that the intensity of the verb affected the students opinion on whether there was any glass on the scene. In actual fact there was no glass present but by challenging the students memory Loftus and Palmer influenced the students to believe otherwise. The actual results were:

Smashed : 16 students claimed they could remember seeing broken glass whereas 34 said there was none present.

Hit : 7 students remembered glass but 43 were correct in thinking there was none.

No Question: 6 students could recall broken glass and 44 could not.

From their study Loftus and Palmer concluded that the verb also played a part in the misperception of broken glass in the film.

Ecological Validity

The investigation was carried out under laboratory conditions and the ecological validity is disputed. People are not likely to act the same in the laboratory as they would in a court. Therefore, responses given might not be entirely accurate. Also, there would have been demand characteristics as the participants were expecting to be questioned in some way about the video and would pay more attention to the happenings in the video than to a normal road. In real life, the accident is completely unexpected and more likely to be forgotten. Furthermore, the emotional aspect - shock, fear, sadness - is taken away, whilst these factors can strongly influence memory and interpretation of events.

References

1. ^ http://www.qeliz.ac.uk/psychology/Loftus%20and%20Palmer.htm
2. ^ http://www.holah.karoo.net/loftusstudy.htm
3. ^ http://www.garysturt.free-online.co.uk/loftus.htm
4. ^ http://www.holah.karoo.net/loftusstudy.htm
5. ^ http://www.holah.karoo.net/loftusstudy.htm
6. ^ http://www.holah.karoo.net/loftusstudy.htm