Erik Erikson focused on the influence of social interaction, "unlike Freud, who attributed the formation of personality only to interaction within the family origin of a person". (Ward & Hisley 2015) Erikson identified seven stages of development. The first stage is trust versus distrust, the second stage is autonomy versus shame and doubt, the third stage is initiative versus guilt, the fourth stage is industry versus inferiority, the fifth stage is identity versus role confusion, the sixth stage is intimacy versus isolation, and the seventh stage is that of generativity versus stagnation. When children are in the initiative versus guilt stage, 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 for a 3-year-old is 32 pounds. Infant fat loss and growth cause the baby to look stronger and less mature. The length of the skull also increases, making the lower jaw more distinct. The upper jaw widens, making room for the permanent teeth. Psychosocial development describes the child as a curious learner, very eager and enthusiastic about learning new things. They feel a shared sense of accomplishment and satisfaction when they succeed in tasks. Allowing them to help with a simple task like packing lunch for preschool encourages their development. They like to please their parents, can take out their frustrations on other siblings, and love to explore new things. They also develop an understanding of rights and rules. An unfamiliar place like a hospital is mostly quite difficult. They may panic or throw a tantrum when their parents leave; a little worry about parental abandonment is normal. They often regress and commonly show signs of eating and sleeping disorders. It's 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 is developed at birth and should be maintained throughout the preschool years. The sense of smell and touch develop during the preschool years. At this age, their sense of taste is still developing, so it may put them at greater risk of accidental ingestion. At this age, babies like to put things in their mouths, nostrils and ears. Visual activity should be equal bilaterally and continue to progress. Typically, their visual acuity is 20/40 or 20/30. Color vision is also intact