In a study conducted in Borneo during the early 1980s, Mitani and his field assistants observed 151 copulations by arrested males; 144 of the matings were forced.

• 1980年代初期，三谷带著助理在婆罗洲做研究，观察到发育迟滞的雄性交配151次，其中144次是强暴。