The concepts of self and of personal property are young and fragile to a toddler and they often defend their newly recognized territory with great emotion. Consequently, they can become very possessive. At this point, caregivers must introduce the concept of sharing. Toddlers must begin to learn about self-control and social expectations. It is very difficult, however, for a toddler to accept the idea of deliberate self-sacrifice and parents must not have unrealistic expectations of generous behavior in their newly assertive toddler.