Garven, S., Wood, J.M., Malpass, R.S., & Shaw, J.S. (1998). More than suggestion: The effect of interviewing techniques from the McMartin Preschool case. Journal of Applied Psychology, 83, 347-359.
Purpose
In general their purpose was to take an extreme case of a real situation, i.e., an interview protocol used with children in a CSA case against the preschool, to test a couple of effects
1. Can one interview produce the same kinds of memory-distortions found in previous research as a result of several suggestive interviews?
2. What are the "synergistic effects" of using multiple kinds of influential interview techniques in one setting (will use of multiple techniques increase memory distortion)?
Method
Participants-- 66 preschoolers, ages ranged from 3-6 (or there abbots)
Procedure and Design
The IV was "Type of Interview", with two conditions
-- Social Incentive
-- Suggestive control
-- why not use a real control group where children were asked the questions directly, without any sort of influence?
* Age and gender were used as co-variates as well (boys gave more "yes" responses than girls)
The DV was the number of "YES" responses the children gave to each type of question
Manny Morales came into the children's preschools and held a special story party, where he made a production with a big hat, read the story The Hunchback of Notre Dame, passed out special napkins (in all but one case), put stickers on their hands, then passed out cupcakes.
Children were later interviewed about Manny's visit, with some true, and some false questions.
8 misleading questions about things Manny didn't do: Did Manny...
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1. ... tear a book? |
5. ... bump the teacher on his way out? |
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2. ... put stickers on your knee? |
6. ... say a bad word? |
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3. ... break a toy? |
7. ... throw a crayon at a child who was talking? |
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4. ... steal a pen from the teachers desk? |
8. ... tell you a secret? |
4 questions that were leading, but were about things Manny did do: Did Manny...
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1. ... tell you to sit quietly and listen? |
3. ... hand out hunch-back napkins? |
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2. ... take off his hat? |
4. ... put a sticker on your hand? |
Social Influence Condition-- the synergistic group, kids were interviewed with an extreme example of the "McMartin Battery"
1. Opening statement was worded as an Other People form of social influence; children were told that the older children had already been interviewed, then they were influenced with the Promise of Positive Consequences.
2. When children were asked each question, the Other People influence was used; when they answered "yes", they were praised with positive consequence, and "no" responses were scolded with negative consequences
3. When children answered "no", Inviting Speculation techniques were used as well, i.e., "imagine...", as were Asked and Answered techniques.
*these are the five general kinds of influence techniques used on the McMartin Trial, the sixth technique, that is inherent, is Suggestive Questions
Important Results
The battery did lead to a greater proportion of "yes" responses to the leading questions of things that Manny didn't do.
Social incentive vs. suggestive control
-- social incentive kids gave three times as many "yes" responses to the misleading questions than suggestive-only kids
-- social incentive kids gave more "yes" responses to the suggestive but true questions than the suggestive-only kids
First vs second half of the interview
-- social incentive kids gave more incorrect yes responses in the second half of the interview, and kids appeared to require fewer prompts (yes-1) in the second half of the interview (this is called a response preseveration bias, they just got used to saying yes)
Conclusions:
1. The social incentive battery worked-- in just about 4.5 minutes, children's errors rates to misleading and suggestive questions were about 60%
2. the social incentive battery may have lead the children to become more acquiescent, or socially conforming, by the second half of the interview (or they may have just started to perseverate with the yes response)