Attachment is an instinctive system by which infants develop a strong and meaningful relationship with their primary caregiver - the feeling of falling in love that occurs between (usually) parent and child. When children are securely attached to the caregiver, they have a safe base from which to explore the world, recover from stresses, and develop trust in themselves and others.
Attachment is a non-verbal process built through day to day care giving. Each baby has his or her own individual needs and preferences - the proper amount of stimulation and rest, whether they prefer music or quiet, whether they prefer to fall asleep snuggled against a warm body or tucked securely into the crib. The parent's job is to tune in to each individual child's needs and adapt accordingly. Tending to a crying baby, soothing in the way the baby prefers, and providing reliable, consistent care all build attachment.
Luckily, infants are resilient, which means that even when parents make an occasional mistake and respond to a child in a less-than-preferred way, attachment can still be strong and secure. But there are times when attachment can be disrupted. When care giving is unreliable, inconsistent, or conducted without any positive emotion from the caregiver - that is, with no love or affection - the attachment will be insecure. Children may become anxious and insecure, develop learning and emotional problems, and avoid closeness and emotional connection. Frequent changes in caregivers (for example, changes in foster care placement or being raised in an orphanage), prolonged separation from the primary caregiver, abuse and neglect, maternal depression and addiction, and a parent with poor parenting skills can all lead to poor attachment.
Children with poor attachment skills may show a variety of behaviors, including low self-esteem, an inability to deal with stress and adversity, lack of self-control, aggression and violence, depression and apathy, and difficulty with genuine trust, intimacy, and affection. In severe cases children may develop Reactive Attachment Disorder (RAD), a clinically recognized form of insecure attachment. These children are incapable of attaching to a primary caregiver, developing positive relationships with others, or going through the normal developmental processes. Intensive treatment is required when dealing with RAD.
Children who have been adopted or live in foster care are at higher risk for attachment disorders. However, in all but the most serious cases, love, time, patience, and professional help can usually help the child learn to build healthy, loving relationships.