During a routine well-child visit, a nurse is assessing a 6-month-old infant's developmental milestones. At this age, the nurse expects the infant to have achieved specific physical and cognitive skills. The infant should be able to sit without support and may begin to transition from a reflexive grasp to a purposeful grasp. Additionally, the infant should be able to respond to their name and recognize familiar faces.
Based on these developmental milestones, the nurse documents that the infant should display signs of __________ at 6 months of age, including social engagement such as smiling at others and reaching out for toys.