Psychologists study human development across the lifespan from conception to death. This is known as "womb to tomb" psychology. The developmental milestones usually can be categorized as either physical, cognitive, personality or social milestones. Toddlerhood designates the development of children between the ages 1 and 3 years.
Physical Development
The celebrated child psychologist Erik Erikson described how the physical development of a child in his second year of life serves as the foundation for cognitive, personality and social development. As a result of the muscularization of the legs, the child is now able to walk and explore on his own. With the gross motor skill abilities to walk, run and climb, as well as the fine motor skills of grasping and manipulating objects, a toddler experiences less dependence on his parents and an increased sense of autonomy.
Cognitive Development
According to the Swiss child psychologist Jean Piaget, children between the ages of 1 and 3 begin to be able to represent objects with words. Children of this age are able to think symbolically and to refer to objects that are not immediately present, however they are unable to see from the point of view of others. This "egocentrism," as described by Piaget, is evident when asking the toddler what someone standing opposite his viewpoint can see. The typical 3-year-old can only describe what he sees.
Personality Development
Dr. Robert Feldman describes the "rouge test" in which a dab of red makeup is placed on the child's forehead. By the second year all healthy children are able to identify themselves in a mirror and wipe the rouge from their face. Psychologists take this as evidence of a "self concept." A toddler's vocabulary is expanding with favorite words such "mine" and "no," as well as references to his self and to "mommy" and "daddy." This is taken as evidence that the child is "individuating" and seeing himself as a person separate from others.
Social Development
With autonomy and the sense of self, the child is presented with the problem of social interaction. As Erikson describes, the toddler is managing his ability of both self-satisfaction, such as walking to a desired toy, and social manipulation, such as getting someone to bring him the toy. The social development for the child of this age centers on achieving a sense of self while struggling with feelings of shame for his individuation. This, Erikson describes, is a result of the parent who scolds the curious toddler in his "terrible twos."
References
- "Life Span Development: A Topical Approach"; Robert S. Feldman; 2010
- "Child Development: Fifth Edition"; Robert S. Feldman; 2009
- "Touchpoints: Birth to Three"; T. Berry Brazelton, et al.; 2006
- "Childhood and Society", Erik Erikson, 1963
- "The Psychology Of The Child," Jean Piaget; 1969


