Koba Reiko, Izumi Akihiro, Nakamura Katsuki
Department of Animal Models for Human Disease, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Japan.
J Comp Psychol. 2009 Aug;123(3):326-33. doi: 10.1037/a0016219.
The authors examined the ability of Japanese monkeys (Macaca fuscata) to discriminate between sexes based on facial features. The shape and position of facial features (facial morphology) were measured to quantify the differences between sexes. The distance between the chin and nose was longer in males than females, and the outline of the face around the upper jaw and upper face differed between sexes. Using operant conditioning, 2 monkeys succeeded in discriminating sex based on facial pictures. Furthermore, they successfully generalized the discrimination to novel pictures of faces. Tests with morphed pictures of faces revealed that the monkeys used facial morphology to discriminate between males and females. Our results suggest that Japanese monkeys have sexual dimorphism in facial shape and they can use the morphological differences to discriminate conspecific sex.
作者研究了日本猕猴（食蟹猴）基于面部特征区分性别的能力。测量了面部特征的形状和位置（面部形态）以量化性别差异。雄性猕猴下巴与鼻子之间的距离比雌性长，并且上颌和上脸周围的面部轮廓在性别之间也有所不同。通过操作性条件反射，两只猴子成功地根据面部图片区分了性别。此外，它们还成功地将这种区分推广到了新的面部图片上。对面部变形图片的测试表明，猴子利用面部形态来区分雄性和雌性。我们的结果表明，日本猕猴在面部形状上存在性别二态性，并且它们可以利用形态差异来区分同种个体的性别。
