Final answer:
Stimulation should be slightly more complex than the child's functioning level to align with the zone of proximal development for optimal learning and cognitive growth without causing frustration.
Step-by-step explanation:
The appropriate level of stimulation should be slightly more complex than the child's functioning level. This concept aligns with the zone of proximal development (ZPD), a theory developed by psychologist Lev Vygotsky. ZPD suggests that children learn best when new information is just beyond their current level of understanding, providing them with a achievable challenge that promotes cognitive growth.
Therefore, tasks and stimulation should be incrementally more challenging to effectively engage and advance their learning and development. For example, if a child has mastered two-piece puzzles, introducing them to three or four-piece puzzles would be slightly more complex and encourage development without causing frustration or disinterest that might occur with a much more complex task.