A Level Psychology at Spalding Grammar School

Loftus & Palmer (1974) Reconstruction of automobile destruction

1974 was a year to forget. A global recession hit the world hard, forcing up the price of food and energy and sending inflation over 17%. On British motorways, the speed limit was lowered to force motorists to save fuel. To make matters worse, the IRA began its terrorist bombing campaign. setting off bombs at the Tower of London, the Houses of Parliament and pubs in Birmingham and Guildford. The charts were full of music to forget as well: 1974 brought us Eurovision-winners ABBA, the Bay City Rollers, the Osmonds and, err, Gary Glitter. Don't worry... punk was just around the corner...

Elizabeth Loftus is one of the world's most famous female psychologists who has been studying memory for nearly 40 years. Loftus argues that memory is RECONSTRUCTIVE and that most of our memories are in fact very unreliable. She has been used as an expert witness in hundreds of cases involving witnesses with false memories. She has received awards for her "ingeniously and rigorously designed research studies". This 1974 study is a classic lab experiment where the researcher controls as many variables as possible then manipulates the Independent Variables and measures the results.

Download the class resources

Click here to download the PowerPoint slideshow and the lecture notes for this study
Download the Background Handout and the Evaluation Proforma for the Loftus & Palmer study

Further your understanding

Visit Mark Holah's site for an excellent summary of Loftus & Palmer's study, with quizzes and links.

Or if you prefer, Gary Sturt's website has a short summary

Need a one-page summary? OCR's website has a nice poster (PDF format)

Elizabeth Loftus wrote this article for the Skeptical Inquirer. It's about false memories but it links with Thigpen & Cleckley too.

Look at Brian Brushwood's video on YouTube. He's debunking UFOs but he has some great tricks with false memories

Check your memory on the BBC Science & Nature website

Background & context

Most people are very certain about their memories and we all put a lot of store in eye witnesses. If someone says they saw it happen then we tend to believe it, no matter how bizarre or unlikely. Unfortunately, psychology tells us that memories are very unreliable. It's not just that we forget things that did happen, but we also remember things that didn't happen. 

Frederick Bartlett carried out some groundbreaking research into memory in the 1930s. He used the word SCHEMA to describe a mental structure that represents something in the world. You could write down all the things you associate with "mother" and that would be your schema for motherhood - just don't show the list to Sigmund Freud! You could identify your other SCHEMATA (the plural form of "schema") for horror films or psychology lessons. Schemata are very important for helping us arrange our memories.

Bartlett carried out an experiment by showing his participants a Native American folk story about two braves who go fishing and come across a war party of ghosts. The story is very strange with an ambiguous ending and Native American ghosts are clearly not the same as European ghosts. When Bartlett asked the participants to recall the story minutes, days or even years later, he noticed they all made similar changes to the story in their memories:

  • Simplify: People made the story simpler, usually by forgetting details and descriptions. They particularly tended to forget details that "made no sense" in their culture - though they were very important details for the Native Americans who created the story
  • Elaborate: People would add new details to the story. In particular, they added details that made the story a more conventional ghost story (from a European point-of-view)
  • In other words, how people remembered the story was shaped by their schema for "ghost story" and "Native Americans", not what was actually in the story

Elizabeth Loftus took up Bartlett's ideas 40 years later when she was looking at testimony given in court and she uses his schema-theory in her own conclusions.

Leading questions are important for understanding several other studies: Samuel & Bryant replicated the conservation experiment because they believed it had leading questions; Freud has been accused of setting leading questions for Little Hans; and leading questions may have created the multiple personalities in Thigpen & Cleckley.

Aims

Loftus wanted to see how influenced people were by LEADING QUESTIONS when trying to estimate the speed of vehicles in a traffic accident. A leading question contains clues that suggest to the listener what answer they ought to give.

Loftus carried out a second experiment to test the effect of leading questions a bit further. This second test aimed to find out if leading questions just prompt a RESPONSE BIAS (or demand characteristics - giving the answer the researcher is looking for) or if they actually cause a person's memory to change.

Method & procedure (1)

Loftus recruited an opportunity sample of 45 college students. These students gathered in groups of 5 and sat in a classroom watching 7 film clips of different traffic accidents, all taken from a road safety film.

After each clip the students had to fill in a questionnaire with some very specific questions about what they remembered seeing. In fact, most of the questions were distractor questions but just one of the questions was the CRITICAL QUESTION - this question was about the speed of the car in the film clip.

I.V.s & D.V.s (1)

The Independent Variable was the wording of the critical question, because each group of students had been given a slightly different questionnaire. The first question was:

  • "About how fast were the cars going when they hit each other?"

The other groups were given a slightly different question, using a different verb to describe the crash:

  • "smashed into each other"
  • "collided with each other"
  • "bumped each other"
  • "contacted each other"
The Dependent Variable was the participant's estimate of the speed in the clip.

Outcomes (1)

The mean average speed was calculated for each group, shown on this table:

 Verb Used
Mean Speed (mph)
 Smashed40.8
 Collided39.3
 Bumped38.1
 Hit34.0
 Contacted31.8

The more intense the verb used in the question, the higher the estimate of speed.

Conclusions (1)

Obviously, leading questions have a big effect on the way people answer. Loftus & Palmer suggest two explanations for this:

  1. RESPONSE-BIAS: people don't really know or remember the speed of the car, but they give an answer based on what the question seems to be looking for
  2. MEMORY ALTERATION: the critical word actually changes the person's memory of the accident, causing them to perceive it as more serious, with faster cars
If memories really are altered by leading questions, you would expect people to "remember" other false details too. Loftus & Palmer tested this in their second experiment.

Method & Procedure (2)

This time Loftus & Palmer recruited an opportunity sample of 150 college students. The students watched a one-minute film clip containing a multiple car accident. Again, they were given a questionnaire to fill in and again most of the questions were distractor questions apart from a critical question about the speed of the main car.

The students were asked to return to the psychology lab a week later. They were asked some more distractor questions but mixed in was another critical question about other details they recalled from the film clip.

I.V.s & D.V.s (2)

The students were divided into three groups of 50. Each group got a different critical question about speed:

  • "How fast were the cars going when they smashed into each other?"
  • "How fast were the cars going when they hit each other?"
  • CONTROL GROUP: This group was not asked a question about speed, so their memories should be unaffected

The Dependent Variable was their answer to the second critical question, one week later, which was:

  •  "Did you see any broken glass?"
In fact, there was no broken glass in the film but participants who thought the collision was fast or violent might be fooled into "remembering" non-existant glass.

Outcomes (2)

The "smashed" group remembered the cars travelling faster on average (10.5mph), compared to the "hit" group (8.0mph).

The answers to the broken glass question are shown on this table:

Verb Used
Remembered Broken Glass?
Smashed
16/50
Hit
7/50
CONTROL GROUP
6/50

Conclusions (2)

Most participants remembered the crash accurately, with no broken glass. Participants who were asked about the speed with a neutral word ("hit") had about the same number of false memories as the control group. But asking the speed question with the leading word ("smashed") massively increased the number of false memories of broken glass.

This ties in with Bartlett's idea of SCHEMA: the participants in the experiment had a schema of a car accident and because the schema of a car accident at speed includes "broken glass", then some of them remembered broken glass if they believed the cars had been travelling fast.

Elizabeth Loftus argues that memory is not a replay of the past, like watching a film recording in your head. Memory is RECONSTRUCTIVE; it's something we create from two sources:

  1. What we perceived during the original event
  2. Information we picked up after the event (like leading questions and schemata)
Over time, information from these two sources merges together so we can't tell what part of our memories are original perceptions and what came later - we just have the one "memory".

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