How does the possession and acceptance of accurate legal and psychological knowledge affect the validity of lay judges' legal judgments?

2010 Fiscal Year Final Research Report

• Project/Area Number: 21830010
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Single-year Grants
• Research Field: Educational psychology
• Research Institution: Ritsumeikan University
• Principal Investigator: YAMASAKI Yuko 立命館大学, 立命館グローバルイノベーション研究機構, ポストドクトラルフェロー (20507149)
• Project Period (FY): 2009 – 2010
• Keywords: 裁判員裁判 / 刑事訴訟法 / 目撃証言 / 評議

Research Abstract

The main results are as follows.
In Study 1, the researcher investigated, from the perspectives of accuracy and acceptance, the kind of legal and psychological knowledge required for conducting a trial, and extracted the kind of knowledge that lay people had difficulty accepting.
In Study 2, the researcher examined whether teaching increases the accuracy and acceptance of the knowledge extracted from Study 1.The results show that it become fully effective in accuracy and partially in acceptance.
In Study 3, the researcher held a mock trial to examine whether teaching influenced the participants' deliberations. The results show that teaching increased the number of mock juror's statements that were based on the psychological knowledge required for conducting a trial. An implication of this result is that teaching enhances the validity of lay judges' deliberations.

Research Products

• [Journal Article] 法と心理学の協働の実際-裁判員制度研究と心理学的解剖研究に接する心理学者の立場から (2010)
  • Author(s): 山崎優子・入山茂・荒川歩
  • Journal Title: 法と心理 Volume: 9 Pages: 51-56
  • Peer Reviewed
• [Journal Article] よりよい裁判員制度の実現を目指す札幌での取り組み (2009)
  • Author(s): 山崎優子・中山博之・坂口唯彦・綱森史泰・広川雅之
  • Journal Title: 法と心理 Volume: 8 Pages: 73-77
  • Peer Reviewed
• [Journal Article] Citizen's psychological knowledge, legal knowledge, and attitudes toward participation in the new Japanese legal system, Saiban-in seido Psychology
  • Author(s): Naka, M., Okada, Y., Fujita, M., & Yamasaki, Y
  • Journal Title: Crime & Law Volume: (印刷中)
  • Peer Reviewed
• [Presentation] 死刑と向き合う裁判員 (2010)
  • Author(s): 福井厚・山崎優子・高山佳奈子・藤田政博・森久智江
  • Organizer: 法と心理学会
  • Place of Presentation: 立命館大学(朱雀),京都
  • Year and Date: 2010-10-17
• [Presentation] 裁判員制度と認知心理学 (2010)
  • Author(s): 伊東裕司・小山雅亀・竹村和久・山崎優子
  • Organizer: 認知心理学会
  • Place of Presentation: 西南大学,北九州
  • Year and Date: 2010-05-29
• [Presentation] 法的推論と法教育しろうとと専門家の推論の違いから考える (2010)
  • Author(s): 長谷川真理子・外山紀子・木下麻奈子・山崎優子・仲真紀子・梅田比奈子
  • Organizer: 発達心理学会
  • Place of Presentation: 神戸国際会議場,神戸
  • Year and Date: 2010-03-28
• [Presentation] 事件報道の接触と説示の提示が裁判員の法的判断に及ぼす影響 (2009)
  • Author(s): 山崎優子・石崎千景・仲真紀子
  • Organizer: 法と心理学会
  • Place of Presentation: 國學院大學,東京
  • Year and Date: 2009-10-25
• [Presentation] 録画された子どもへの面接:証拠としての価値と法廷における問題 (2009)
  • Author(s): 上宮愛・山本健一・岡田悦典・山崎優子・仲真紀子
  • Organizer: 法と心理学会
  • Place of Presentation: 國學院大學,東京
  • Year and Date: 2009-10-24
• [Presentation] The influence that news report and a judge's instruction exert on lay judges' information processing and decision making (2009)
  • Author(s): Yamasaki, Y., Naka M., & Ishizaki, C
  • Organizer: The 11th European Congress of Psychology
  • Place of Presentation: Oslo, Norway
  • Year and Date: 2009-07-10
• [Book] Azusa Shuppann, Towards A Healthier Judicial System : The effectiveness of legal and psychological instruction for lay judges, Lai, W. L., Sakurai, Y., & Wada, H.(Eds). A study of healthy being (2010)
  • Author(s): Yamasaki, Y
  • Total Pages: 138-152
• [Remarks] 山崎優子,市民の望む刑罰と報道の影響,立命館大学衣笠総合研究機構主宰土曜講座, 2010年9月25日,立命館大学(衣笠),京都