Erik Erikson focused on the influence of social interaction, "unlike Freud, who attributed the formation of personality solely to interaction with within a person's family of origin. » (Ward & Hisley 2015) Erikson identified seven stages of development. The first stage is confidence against distrust, the second stage is self-reliance against shame and doubt, the third stage is initiative against guilt, the fourth stage is industry against inferiority, the fifth stage is identity versus role confusion, the sixth stage is intimacy versus isolation. , and the seventh stage is generativity versus stagnation. When children are in the stage of initiative rather than guilt, they "begin to assert their power and control over the world through direct play and other social interactions." The average 3-year-old is about 37 inches tall. The average weight gain is about 5 pounds per year. The average weight of a 3 year old is 32 pounds. Fat loss and baby growth make the child appear stronger and less mature. The length of the skull also increases, making the lower jaw more distinct. The upper jaw widens, making room for permanent teeth. Psychosocial development describes the child as a curious learner, very eager and enthusiastic about learning new things. They feel a common sense of accomplishment and satisfaction when they succeed in activities. Allowing them to participate in a simple task like preparing their lunch for kindergarten encourages their development. They like to please their parents, they can take out their frustrations on other siblings and they like to explore new things. They also develop understanding of law and welfare. An unfamiliar place like a hospital is usually quite difficult. They may panic or throw tantrums when their parents leave; a little worry about leaving your parents is normal. They often regress and frequently show signs of eating and sleeping disorders. It is a good idea for a child to use play therapy as an emotional outlet, and play therapy can also help parents understand their child's sense of reality. Sensory development begins at birth and should continue throughout the preschool years. Smell and touch develop throughout the preschool years. At this age, their sense of taste is still developing, which may put them at greater risk of accidental ingestion. At this age, children like to put objects in their mouths, nostrils and ears. Visual activity should be equal bilaterally and continue to progress. Generally, their visual acuity is 20/40 or 20/30. Color vision is also intact at this time