Cognitive Abilities and Social Behavior in Aged Japanese Monkeys

1. 地位较高的老年雄性倾向于与某些成年雌性保持持续的从属关系，这种关系有助于老年雄性保持其较高的统治地位。与年轻女性相比，女性更倾向于把社交活动集中在自己的近亲身上。延迟反应任务的结果显示，30岁以上的高龄雌性视空间记忆受损最严重，不能在野外生存，其次是25-29岁的生殖后雌性，而20岁前半期的雌性在生殖能力下降的情况下仍能保持与20.3岁以下雌性相当的能力。只有在地位较高的亲属群体中，祖母的存在才有利于孙辈在出生后的第一年存活下来。大猩猩母亲的活动可以被认为是她年幼的成年女儿在照顾母婴方面的脚手架。

1. Old high-ranking males tended to maintain continuously affiliative relationships with some adult females, and such relationships are useful for the old males to maintain their high dominance positions. Females are more likely to concentrate their social activities toward their close relatives, compared with younger females.2. The results of delayed response task show that the extremely aged females more than 30 years of age who could not survive in the wild are most heavily impaired in visuospatial memory and that post-reproductive females aged 25-29 years are next, while females in the first half of the twenties whose reproductive ability is decreasing can still maintain their ability which is as high as that for females aged less than 20.3. The presence of grandmothers is beneficial to their grandchildren's survival during the first year after birth in only high-ranking kin-groups.4. A gorilla mother's activities could be considered scaffolding for her young adult daughter with regard to maternal infant care.