The effect of warning against conformity on memory accuracy after cooperative remembering

1. The effect of warning against conformity on memory accuracyafter cooperative remembering Yuji Itoh, Satoshi Umeda, Jun Kawaguchi Keio University University of Nagoya

2. The effect of warning against conformity on memory accuracyafter cooperative remembering Yuji Itoh, Satoshi Umeda, Jun Kawaguchi Keio University University of Nagoya

3. The effect of warningagainst conformity Yuji Itoh, Satoshi Umeda, Jun Kawaguchi Keio University University of Nagoya

4. The effect of warning against conformity: Does it reduce the memory conformity effect? Yuji Itoh, Satoshi Umeda, Jun Kawaguchi Keio University University of Nagoya

5. The effect of warning against conformity: Does it reduce the memory conformity effect? Yuji Itoh, Satoshi Umeda, Jun Kawaguchi Keio University University of Nagoya

6. The effect of warning against conformity: Does it reduce the memory conformity effect? Yuji Itoh, Keio University

7. The effect of warning against conformity: Does it reduce the memory conformity effect? Yuji Itoh & Mayumi Harada Keio University

8. The effect of warning against conformity: Does it reduce the memory conformity effect? Yuji Itoh & Mayumi Harada Keio University

9. INTRODUCTION • Memory Conformity Effect • Information from other people during collaborative remembering as misleading information • Kanematsu, Mori, & Mori (1996) • Wright, Self, & Justice (2000) • Reduce or elimination of misinformation effect by source monitoring test • Lindsay & Johnson (1989)

10. Does warning against conformity given after collaborative remembering reduce the memory conformity effect in later remembering? • A preliminary experiment using MORI technique suggested some possibility. • Examined the effect of warning against conformity.

11. ICI paradigm • comparison between BC responses and AC responses independent remembering BC collaborative remembering CR independent remembering AC

12. BC might strengthen memory for the witnessed event and/or source memory. • In many cases, there is no remembering attempt that corresponds to BC for real life eyewitnesses. • Examine the effect of warning to decrease memory conformity when there is no BC.

13. Questions • Does warning after collaborative remembering reduce memory conformity? • Is the effect of warning to decrease memory conformity smaller when participants have no chance to remember the event independently before collaborative remembering?

14. METHOD • Participants • 78 undergraduates (39 dyads) • Apparatus • MORI technique • Each participant in a dyad observed slightly different set of slides.

15. Materials • Sequences of slides that depict a criminal event • 26 slides X 2 • Two sequences are similar to each other except 4 details. • A female thief’s behavior after she stole a purse • The direction to which the pair of thieves went away • Items the female thief possessed • Color of the male thief’s shirt

16. presentation of slide sequence BC recognition test C recognition test C recognition test warning warning AC recognition test warned w BC 7 dyads unwarned w BC 7 dyads control w BC 7 dyads warned w/o BC 6 dyads unwarned w/o BC 6 dyads control w/o BC 6 dyads

17. Recognition items • Critical items: Questions on the details about which a dyad saw different scenes. • 4 items • Non-critical items: Questions on the details about which a dyad saw the same scene. • 22 items

18. RESULT • Change from BC to AC in with BC condition • conformed:

19. conformity ratio • for critical and non-critical items separately • for each participant

20. Conformity ratio for w BC cond • Non-critical items

21. Critical items

22. For both Non-critical and Critical items • number of conformed items and conformity ratio was higher for • unwarned than control condition but not higher for • warned than control condition • unwarned > warned = control

23. To examine the effect of BC • In without BC condition, we can’t calculate the conformity ratio. • Numbers of correspondence in AC responses are an appropriate index of conformity.

24. Effect of BC • Numbers of correspondence in AC • Non-critical items

25. Critical items

26. DISCUSSION • Collaborative remembering makes memory conformity in later independent remembering. • information from others as a source of misinformation effect

27. Warning against conformity reduce this memory conformity effect • if there is independent remembering attempt before collaborative remembering

28. Non-critical items Critical items

29. Warning against conformity reduce this memory conformity effect • if there is independent remembering attempt before collaborative remembering • if and only if?

30. Non-critical items Critical items

31. Warning against conformity reduce this memory conformity effect • if there is independent remembering attempt before collaborative remembering • if and only if? probably… We need more data!

32. To compare w BC with w/o BC • Conformity and responses in CR and AC • conformity and number of items with same AC responses • correlations are moderately high

33. conformity and change from discrepancy to correspondence • For all cases where a pair of responses were not same in BC and same in AC, conformities were observed. • There were a few cases where no such changes were observed whereas conformities were observed. • Each member of a pair conformed to the other.

35. Numbers of correspondence in BC responses are expected to be same for warned, unwarned, and control conditions. • the extent to which individuals’ memories for each item correspond in a dyad • Numbers of correspondence in AC should be an appropriate index of conformity.