The attachment bond involves a baby's biological motivation to connect, interact, communicate and feel safe. This link is given with its mother or adult that replace her.
The attachment doll is a material object in which the baby lays some affection. It has significant physiological functions, especially to learn to sleep alone, or in times of conflict. The adoption of the attachment doll gives him security, comfort and companionship and helps him recognize himself as independent of other beings around him.
  According to experts, children placed in transitional objects a number of feelings and emotions that allow them to keep in touch with his mother (at least symbolically).
   The duration of this need depends on many factors, for example, the child's personal circumstances, the intensity of emotions involved and how the parents are handling the situation. Although in most cases tends to disappear between 3 and 4 years of age, some experts indicate no objection to last until 5 or 6 years. The transitional object becomes so important in the life of the child that accompanies him most of the day,gives him comfort and becomes indispensable at the sleeping time. It's something that gives security. Represents the attachment  the baby has with her parents and helps control the anxiety of separation.