Final answer:
Babies as young as 3 months old have shown the ability to understand properties of objects, indicating they can perceive occluded objects. Studies refute the earlier perception of depth and size constancy at such an early stage, which aligns with the development of motor skills and engagement with the environment.
Step-by-step explanation:
Research in the field of developmental psychology has provided insight into the cognitive development of infants. A notable finding is that babies can demonstrate knowledge of the properties of objects much earlier than previously believed. In a study by Baillargeon, infants as young as 3 months old showed an understanding of the properties of objects. They anticipated that solid objects cannot pass through each other, indicating early cognitive abilities pertaining to the perception of occluded objects. This study suggests that the statement "Researchers have found that babies have perception of occluded objects as young as 3 months of age." would be correct. The infants spent a significant amount of time looking at impossible events, such as a truck rolling past an object that appeared solid, and this prolonged gaze signified their expectations were violated.
Depth perception and size constancy both develop after infancy, aligning with motor skills and physical mobility. As babies grow and engage more with their environment, these perceptual abilities improve. However, the referenced study emphasizes that the understanding that things continue to exist, even when out of sight, starts to form much earlier than other aspects of cognitive perception, such as depth perception.