1. Some of your best ideas are mine: unconscious antiplagiarism Nicholas Lange, Timothy J. Perfect and Ian Dennis

2. Standard Paradigm Brown & Murphy (1989): – Semantic category examplar generation – Recall after a delay followed by generate-new phase – Higher plagiariasm than intrusion rates – Plagiarism rates above chance Brown, A. S., & Murphy, D. R. (1989). Cryptomnesia: Delineating inadvertent plagiarism. Journal of Experimental Psychology: Learning, Memory, and Cognition, 15(3), 432–442.

3. Standard Paradigm Generation

4. Standard Paradigm Plagiarism Recall

5. Standard Paradigm Generate New

6. Standard Paradigm Plagiarism Cryptomnesia Macrae, C. N., Bodenhausen, G. V., & Calvini, G. (1999). Contexts of Cryptomnesia. Social Cognition, 17(3), 273–297.

7. Standard Paradigm

8. If source misattribution bias is self-serving

9. 47 participants Mixed Model design – Task: recall own, recall partner, recall both (between subjects) – Delay: one day, seven days (within subjects) Extended paradigm and delay

11. ** Delay

12. Extended paradigm and delay ** Task

13. Extended paradigm and delay *

14. Plagiarism rates increase with delay More ideas are given away than plagiarised Effects not as pronounced with joint-source recall

15. Source misattribution bias is not exclusively self-serving In fact it appears to be more self- defeating Extended paradigm and delay

16. Background – Macrae, Bodenhausen and Calvini (1999) – Higher rates of plagiarism with female/female vs female/male pairs Extended paradigm and source similarity ♀ ♂ ♀♀ > Macrae, C. N., Bodenhausen, G. V., & Calvini, G. (1999). Contexts of Cryptomnesia. Social Cognition, 17(3), 273–297.

17. 47 participants Mixed Model design – Task: recall own, recall partner, recall both (between subjects) – Source Similarity: high, low (within subjects) – Delay: 1 week Extended paradigm and source similarity

19. * ns Source Similarity

20. Extended paradigm and source similarity ** Task

21. Extended paradigm and source similarity * * * ns similarity task

22. More ideas are given away than plagiarised Wrong-source error rates increase with high similarity Recall partner task drives similarity effect – vs. Macrae, Bodenhausen & Calvini (forced recall? between vs within factor?) Joint source recall does not show an effect of source similarity Extended paradigm and source similarity

23. …and unconscious anti-plagiarism -> wrong-source errors / source misattributions Increase with delay and source similarity also with increased typicality of items, increased similarity of items and instruction to output liberally Unconscious plagiarism?

24. Extended paradigm and delay Generation phase First recall session A B Set of generated examples per category 1d delay Recall Both Recall Own Target in recall Participant used in example Additional 6d delay Recall Partner Second recall session t B AB A B A B AB A B A Recall Partner

25. Extended paradigm and source similarity Generation phase Recall phase ♀ ♂ Set of female male generated examples per category 7d delay Recall Partner Recall Both Recall Own ♂ ♀ Target in recall Participant used in example t ♀ ♂ ♀ ♂ ♀ ♀ ♂ ♀ ♀

26. Extended paradigm and delay Single Source Recall

27. Extended paradigm and delay Recall Both

28. Extended paradigm and source similarity -Effect of task on: -Correct recall, RO > RP -Wrong-Source Errors, RO < RP -Intrusions, RO < RP -Effect of similarity on: -Correct recall, High < Low -Wrong-Source Errors, High > Low -Intrusion, High = Low

29. Extended paradigm and source similarity -Effect of task on: -Correct recall, RO > RP -Wrong-Source Errors, RO < RP -Intrusions, RO < RP -Effect of similarity on: -Correct recall, High = Low -Wrong-Source Errors, High = Low -Intrusion, High = Low