Attachment theory is a psychological, ethological and evolutionary theory that provides a descriptive and explanatory framework for understanding interpersonal relationships between human beings. Presented by John Bowlby, the important principle of this theory is that a child needs to develop a relationship with at least one primary caregiver in order for social and emotional development to progress overall. The idea of ​​attachment theory is that children become attached to adults who are sensitive and responsive in social relationships with them, and who remain consistent caregivers for a few months in the period from the first six months to two/three years of age. In his early days, Bowlby was criticized by academic psychologists and even ostracized by the psychoanalytic community, but attachment theory has become a dominant approach in understanding social development and has given rise to empirical research on the formation of close relationships between children. The child observed for this article is my 5 year old nephew. He is currently in first grade and has few characteristics of an anxious and ambivalent child (discussed in the story). HistoryAfter graduating from Cambridge University in 1928, Bowlby did voluntary work at a school for disturbed children while he reconsidered his career goals. Her experiences with two children at school kicked off her professional life. One was a very isolated, remote, and loving teenager who had been expelled from his previous school for stealing and had no stable maternal figure. The second child was an anxious 7 or 8 year old who followed Bowlby around and was known as his shadow (Ainsworth, 1974). Persuaded by this experience of the effects of early family relationships... half of the document ......how attachment in early childhood is necessary for the healthy development of the child. It is necessary for children to have a sense of security so that they can grow into healthy, productive adults, but if attachment to them is lacking, they are at a higher risk of developing social, emotional, or behavioral problems during childhood or adolescence . Insecure attachment developed because the person who cares for the child (the mother) did not always respond to him in a warm, affectionate, loving, reliable and sensitive way. These children are more likely to develop a mental representation of the world as hostile or indifferent which leads to many psychological disorders. Adolescents who have not developed a secure attachment tend to be open to depression and anxiety and are more likely to be involved in drug abuse and antisocial/sexual activities. (Doyle, 2000)