Final answer:
An item on a developmental continuum is the rooting reflex in newborns, serving as a milestone in infant development for survival. Development is either continuous or discontinuous, with milestones occurring in a predictable sequence despite influences from culture or environment.
Step-by-step explanation:
An example of an item that would be seen on a developmental continuum could be the reflexes observed in newborns. These newborn reflexes are critical for survival and represent the early stages of motor skill development. For instance, the rooting reflex, which is the tendency for infants to turn their head toward anything that strokes their cheek or mouth, is a key milestone in infant development that supports feeding and ensures the infant's growth and survival.
Developmental psychologists view growth as either a continuous development—where improvements on existing skills happen gradually over time—or as a discontinuous development—where changes happen in unique stages at specific times or ages. The sequence of developmental milestones, such as the rooting reflex, represents a series of predictable steps that are typically similar for all infants and occur in a set order, underscoring the concept of a developmental continuum.
Similarly, cross-cultural studies like those involving language development and motor skills confirm that while the context and environment might influence the rate of development, the sequence in which these developmental milestones occur remains largely universal across different cultures.