**Rationale for review:** A growing body of literature suggests that female adult rape complainants who appear distressed while recounting the alleged assault event are perceived to be more credible than complainants who appear emotionally ‘flat’ (e.g. Kaufmann et al., 2003 cf. Vrij & Fischer, 1997). This is problematic as rape complainants may present a range of emotional reactions while discussing the assault event including distress, anger or flat or controlled affect (Konradi, 2007). Emotional demeanour of the complainant influences a range of key decisions about progressing rape complaints through the criminal justice system including police recommendations to prosecute (Jordan, 2004), prosecutors’ decisions to proceed to trial (Frohman, 1991), jurors’ decisions about witness credibility and verdict (e.g. Hackett, Day & Mohr, 2008). This systematic review, meta-analysis and p-curve analysis aims to investigate the direction and robustness of the effect of female adult complainant emotional demeanour on perceived complainant credibility.
**Aims and Hypotheses:** The main aim of this meta-analysis is to assess the direction and robustness of the effect of emotional victim demeanour on perceived credibility of the witness for adult female complainants of rape. We also want to explore the effect of stimuli modality and sample type on this effect. We expect that the effect of complainant emotional demeanour on perceived credibility will be greater when perceivers have viewed video of the complainant compared to when they have read a synopsis in which the complainant’s emotional demeanour is described. We also want to explore whether there is any change in the emotional victim effect between perceivers with training or experience in the criminal justice system (i.e. police officers, lawyers, judges etc) and lay perceivers (i.e. mock jurors and community members).
**Data collection to date:** A scoping review including searches of the Centre for Reviews and Dissemination (DARE), the Campbell Collaboration and the International Prospective Register of Systematic Reviews (PROSPERO) databases using the key words victim, rape, sexual assault and jury has been completed. No published or in-progress reviews on this topic were found. The systematic searches for papers that meet the inclusion criteria are in progress. As the systematic searches and data extraction is not yet complete, no analysis has been undertaken on the data.
**Systematic search strategy:** The systematic review for papers to include in the meta-analysis will be executed and reported according to the PRISMA guidelines (Moher et al., 2009). To identify eligible papers, systematic searches of several databases that index psychology and criminology journals (PsycINFO, Scopus and Web of Science) will be undertaken. Some initial searches of ProQuest Social Sciences were undertaken but as the database does not index many empirical psychology journals this database has been excluded from the systematic searches. This systematic review will include grey literature. To capture grey literature, searches of ProQuest Dissertations and Theses and OpenGrey will be undertaken. Searches conducted in Web of Science will also include grey literature. In addition to database searches, several ‘snowballing’ techniques will be used to find additional relevant papers. To search for additional eligible papers, the reference lists of papers that meet the inclusion criteria will be manually searched, Google scholar searches will be conducted for all authors of included papers and ‘cited by’ searches will be conducted for included papers in Web of Science and Google Scholar. To search for additional grey literature, email requests for unpublished manuscripts, studies and dissertations will be sent to several psychology listservs.
**Inclusion criteria:** To be included in this meta-analysis, studies must meet all of the following inclusion criteria:
(1) Studies must be reported in English
(2) Studies must be empirical (e.g. no opinion pieces or legal commentary)
(3) Studies must sample adults (18 years of age and older)
(4) Studies must manipulate the emotional demeanour of a female adult complainant of sexual assault or rape
(5) Studies must measure perceptions of a female adult complainant of sexual assault or rape (i.e. perceived credibility of the complainant)
**Planned analyses:** Studies must meet all of the inclusion criteria to be included in the meta-analysis and report information necessary for effect size to be calculated. The meta-analysis will be executed in R using the metafor package (and the meta or mvmeta packages if required). To be included in the p-curve analysis, studies must be included in the meta-analysis and meet the guidelines for inclusion in a p-curve analysis (Simonsohn, Nelson & Simmons, 2014). For the p-curve analysis, the procedure for selecting (and disclosing) p-values for the analysis provided by Simonsohn, Nelson & Simmons (2014) will be followed. The p-curve, and associated statistics, will be generated using the online p-curve app available at: http://www.p-curve.com/
**References:**
Frohmann, L. (1991). Discrediting victims' allegations of sexual assault: Prosecutorial accounts of case rejections. Social Problems, 38(2), 213-226.
Hackett, L., Day, A., & Mohr, P. (2008). Expectancy violation and perceptions of rape victim credibility. Legal and Criminological Psychology, 13(2), 323-334. doi:10.1348/135532507X228458
Jordan, J. (2004). Beyond Belief?: Police, Rape and Women’s Credibility. Criminal Justice, 4(1), 29-59. doi:10.1177/1466802504042222
Kaufmann, G., Drevland, G. C. B., Wessel, E., Overskeid, G., & Magnussen, S. (2003). The importance of being earnest: displayed emotions and witness credibility. Applied Cognitive Psychology, 17(1), 21-34. doi:10.1002/acp.842
Konradi, A. (2007). "I don't have to be afraid of you": Rape Survivors' Emotional Management in Court Taking the stand: Rape survivors and the prosecution of rapists (pp. 97-117): Greenwood Publishing Group.
Moher, D., Liberati, A., Tetzlaff, J., Altman, D. G., & The, P. G. (2009). Preferred Reporting Items for Systematic Reviews and Meta-Analyses: The PRISMA Statement. PLOS Medicine, 6(7), e1000097. doi:10.1371/journal.pmed.1000097
Simonsohn, U., Nelson, L. D., & Simmons, J. P. (2014). P-curve: a key to the file-drawer. Journal of Experimental Psychology: General, 143(2), 534.
Vrij, A., & Fischer, A. (1997). The Role of Displays of Emotions and Ethnicity in Judgments of Rape Victims. International Review of Victimology, 4(4), 255-265. doi:10.1177/026975809700400402
