What is the key achievement of the sensorimotor stage?

• Ability to think abstractly

• Understanding object permanence

• Development of symbolic play

• Grasping the concept of conservation

Why do children in the pre-operational stage struggle with understanding different perspectives?

• Lack of logical thinking

• Egocentrism

• Inability to classify objects

• Lack of abstract thinking

At what stage do children begin to understand the concept of conservation?

• Formal operational stage

• Concrete operational stage

• Pre-operational stage

• Sensory-motor stage

What ability is developed during the formal operational stage?

• Symbolic play

• Logical thinking about concrete events

• Object permanence

• Abstract and hypothetical thinking

Who is known for criticizing Piaget's theory of cognitive development?

• John Watson

• Lev Vygotsky

• Sigmund Freud

• Erik Erikson