The genus ape has a remarkable affection for its young. Tame monkeys kept in the house who bear young ones carry them about and show them to everybody, and delight in having them stroked, looking as if they understood that they are being congratulated; 猿猴特别喜欢自己的孩子，被驯养的猴子会抱着自己的幼崽到处给人看，被抚摸幼崽时会高兴，似乎明白自己受到祝贺。——老普林尼《自然志》第八卷216