Key Figures & Theories
Arguably the most influential figure in child development is Jean Piaget and his theory of cognitive development. Piaget was a Swiss psychologist that believed children learn through hands on experience, have successes and failures, then use these successes and failures to form their own mental representation of the world. Piaget also believed that children learn in a reliable, staged manner (i.e., they go through different stages of development) and move from one stage to another once they achieve specific developmental milestones.
Piaget's called this theory the Theory of Cognitive Development, and included four stages: Sensorimotor, Preoperational, Concrete Operational, and Formal Operational.
• Sensorimotor Stage occurs from Birth - 2 years. During this stage children experience the world through their senses and actions such as touching, looking, etc. Once the child accomplishes the milestones of Object Permanence (i.e., the knowledge that an object exists even when hidden from view) and Stranger Anxiety they've successfully completed this stage and move to the next stage.
• Preoperational Stage occurs from 2 years - 6 years. During this stage, children are able to represent the world with words and images, but they're still not able to use true logical reasoning. Developmental milestones are pretending and egocentrism.
• Concrete Operational Stage occurs from 7 years - 11 years. During this stage, children learn Conservation: that the quantity of concrete materials (objects, liquids) remains constant even if the organization and/or shape changes (see video). For example, pouring liquid into glasses of different sizes does not change the amount of liquid. In other words, they learn that a change in shape does not mean there's a change in quantity or volume.
• Formal Operational Stage occurs from ~12 year through adulthood. During this stage, children learn to use abstract reasoning. This is a major step as reasoning now goes beyond the concrete (requiring actual experience) to abstract thinking that involves symbols and imagination. A milestone at this stage is the potential for moral reasoning.
Just like Piaget believed we pass through stages of cognitive development, Erik Erikson stated that children pass through stages of psychosocial development. Each stage of development has a specific conflict (the conflict is also the name of the stage) that the child has to overcome before moving to the next stage. If a child is unable to successfully overcome a particular conflict, the child will remain stuck at that stage until he or she is able to resolve that issue. The stages of Erikson's psychosocial development are as follows...
• Trust vs. Mistrust (this is the stage and the conflict) occurs from birth to 1 year. To resolve this conflict, the child must develop a sense of security
• Autonomy vs. Shame and Doubt occurs from age 1 - 2. T