Which is NOT a primary tendency within the order Primates?

Nocturnality is considered a secondary adaptation rather than a primary tendency within the order Primates. While some primates are indeed nocturnal, the majority are diurnal, which means they are active during the day. In contrast, social living, tree-dwelling (arboreal adaptation), and visual acuity are recognized as primary tendencies that characterize many primate species:

• Social living refers to the common tendency among primates to form complex social groups that facilitate cooperation, communication, and social learning.
• Tree-dwelling adaptations highlight the evolution of many primate species that live in arboreal habitats, allowing them to exploit resources in the forest canopy.
• Visual acuity relates to the evolutionary development of forward-facing eyes, which enhances depth perception and is vital for navigating complex three-dimensional environments in trees.

Thus, while nocturnality is a trait observed in some primates, it does not represent a fundamental characteristic across the entire order.