According to Jean Piaget's theory of cognitive development, what is the duration of the 'Pre-operational Stage'?

→ According to Piaget, during the first stage of development (birth to approximately 2 years of age), an infant learns best: → Under Jean Piaget's theory of cognitive development, upon detailed analysis of the essential and logical limitations of the 'Preoperational Stage', which of the following statements is scientifically most valid regarding the concepts of 'Egocentrism', 'Irreversibility', and 'Animism'? → According to Piaget, in which stage of cognitive development does a child begin to think logically about concrete objects and events? → According to Piaget, what is 'Assimilation'? → According to Jean Piaget's theory of cognitive development, the quality of 'conservation' develops in which stage? → According to Jean Piaget, in which stage of cognitive development does a child learn the quality of 'conservation'? → According to Jean Piaget, the trait of 'Object Permanence' develops in which stage? → In the context of Jean Piaget's theory of cognitive development, consider the following statements: 1. According to Piaget, the concept of 'Conservation' develops primarily during the 'Pre-operational Stage', in which the child understands that even if the form or shape of an object changes, its quantity or mass remains unchanged. 2. The quality of 'Object Permanence' is a very important achievement of the 'Sensorimotor Stage', upon the development of which the child begins to understand that objects continue to exist even when they are out of sight. 3. The 'Formal Operational Stage' begins around 11-12 years of age, in which adolescents fully develop the capacity for 'Abstract Thinking' and 'Hypothetical-Deductive Reasoning'. 4. Piaget believed that children construct their knowledge actively by themselves, and the nature of their thinking differs from that of adults only quantitatively, not qualitatively. Which of the above statements are correct?