Studies point out that infants exhibit behavioral reactions reminiscent of emotional states as early on as the first three or four months of after birth. The four initial emotional states they appear to experience are distress (this is as a result of uneasiness), relaxation, surprise, and excitement. By the time the infant is one year old, new emotional states such as fear, sadness, and anxiety already have appeared. The central emotional feat for infants, on the other hand, is in all probability the founding of lasting emotional bonds with their parents or other caregivers. Actually, according to studies, all infants are predisposed biologically to form such attachments. These bonds form the foundation for healthy social and emotional development through their childhood. It is in the course of these reciprocal interactions involving child and parent that the child learns to love, confide, trust, and depend on others.
Beginning from the early months on, the baby builds attachments with those who care for him or her, as well as on the basis of their actions, begins to increase expectations of gratification (for example the way adults respond to cries of distress). In addition, social smiling appears early, and by the final part of the first year the baby possibly will depend on the company of known faces and become nervous in the company of strangers.
According to Ainsworth (1978) there are three major attachment styles. These include: secure attachment, ambivalent-insecure attachment, and avoidant-insecure attachment. However, researchers Main and Solomon (1986) later added a fourth attachment style called disorganized-insecure attachment based upon their own research.
Failure to form secure attachments during one's infancy can have a detrimental impact on behavior soon after childhood and all the way through that person's life. Children who frequently display attachment problems, possibly due to early abuse, neglect, or trauma have been diagnosed with conduct disorder (OD), oppositional-defiant disorder (ODD), or post-traumatic stress disorder (PTSD).
Whereas attachment styles displayed in adulthood are not essentially similar as those seen in infancy, research suggests that early attachments can have a grave impact on later interaction. For instance, individuals who are securely attached in childhood are inclined to have strong romantic relationships, good self-esteem, and can self-disclose to others.