Infants and toddlers are busy exploring the world. Everything excites them. Your curious 11-month-old will crawl over to the light socket repeatedly to see what it is all about, or jettison food over the side of his tray table to study gravity. At this stage your child is ecstatic about his new physical skills, such as walking and climbing.
At 15 months old, your child is constantly in motion and it will be hard for him to stop. Children in this age group are also egocentric. They experience their wishes and needs as urgent. When you are standing at the checkout counter, your two-year-old's wish for a new toy will feel like life and death to him, so it will be hard for him to let go. Infants and toddlers are impulsive. They lack the ability to express their needs and desires verbally, so they act them out.
Your 18-month-old, for instance, will grab a bag of potato chips from the supermarket shelf or engage in a tug of war over another child's shovel. And when he is angry he might hit, kick or bite. (This behavior is similar to the way a tiny infant thrashes around when he is frustrated.)
Babies are not born with social skills. That is why infants and toddlers have a hard time sharing (giving up a possession is experienced as a loss) or waiting their turn (they cannot tolerate delayed gratification). Your 2-year-old is developing a sense of self, so she will try hard to assert her independence from you. Therefore, at times she will fight you tooth and nail over brushing her teeth or going to the potty.
During these early years, it is crucial to set limits with your child to keep him safe and to teach him important social and emotional skills. At the same time, you must give your child room to explore the world.