Final answer:
Grooming in primates primarily serves to build and maintain affiliations within the group, nurturing social bonds and strengthening family ties.
Step-by-step explanation:
Grooming relationships among primates serve multiple functions within their social structures. One primary purpose of these interactions is to build and maintain affiliations within a group. In the complex social world of primates, grooming is an essential tool for nurturing social bonds, establishing alliances, and reinforcing family ties, particularly among related females at the core of social groups. Grooming also plays a critical role in promoting parental care, as mutually enjoyable interactions like grooming strengthen the parent-infant bond. However, it's important to note that primates exhibit a rich tapestry of behaviors, and grooming can have various meanings depending on the context.