Testamentary Capacity in the Lucid Interval

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K01361
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 05060:Civil law-related
• Research Institution: Otaru University of Commerce
• Principal Investigator: Iwamoto Naoki 小樽商科大学, 商学部, 教授 (80613182)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 遺言能力 / 意思能力 / 法律行為 / 遺言 / 認知症 / 記憶 / 意識清明期 / 認知的浮動

Outline of Final Research Achievements

I studied the effect of dementia on will ability. In the process, it became clear that Japan's Civil Code was enacted without considering the effects of dementia. So I then studied English law. As a result, as in Japan, the relationship between dementia and will ability is disputed in Britain, the memory of the testator is the issue there, and the British court is suspicious of the memory of the testator. It turns out that there is a tendency to affirm the will ability, if any.
In the process of British law research, it was also found that medical research progressed on "dementia and memory". It is also one of the results of this study to present the possibility that these findings can be applied to the problems of will ability and dementia.

Free Research Field

民法学

Academic Significance and Societal Importance of the Research Achievements

高齢化や遺言の普及により、「認知症と遺言」の問題が今後も増大することが予想される。そうした中、本研究は紛争の予防的解決に役立つことが期待される。そして、このことは、ひいては遺言を巡る家庭不和の回避にも貢献するであろう。認知症が遺言能力に及ぼす諸問題の解決は、法学と医学の学際的連携という観点のみならず、より良い社会の実現という観点からも意義を有する。