Final answer:
The claim that all Old World monkeys and apes are very social and live in permanent groups is false; for example, orangutans lead a more solitary existence.
Step-by-step explanation:
The statement that All Old World Monkeys and Apes live in permanent groups and are very social is False. While many species of Old World monkeys and apes, such as gorillas and chimpanzees, do live in social groups, not all exhibit this behavior. For instance, orangutans are known to be more solitary. Sexual dimorphism is common among these primates, often linked to social structures where a single male defends multiple females. However, not all Old World primates adhere to this pattern; for example, the very arboreal gibbons exhibit low sexual dimorphism and live in small family groups, similar to great apes like gorillas, which have strong sexual dimorphism and live in larger groups.
Gorillas and chimpanzees live in family groups with a dominant male, whereas orangutans are generally solitary, indicating that not all Old World primates are permanently social. Additionally, New World monkeys like tamarins and marmosets form pair bonds and cooperatively raise the young, showing a different social structure from Old World species.