I will demonstrate my understanding of how attachment between a child and his or her caregiver is measured by psychologists and whether attachment is essential for successful social development. I will first provide an overview of what attachment is and the main theorists behind its theory. There are two main theories that are central to the foundation of attachments. Attachment behaviorist theory proposes that attachment is a set of behaviors that are learned. The basis for learning attachments is the provision of food. They learn to associate the feeder with the comfort of being fed and, through the process of classical conditioning, come to find contact with their mother reassuring. (Dollard & Miller, 1950) Evolutionary attachment theory (e.g. Bowlby, Harlow, Lorenz) proposes that children come into the world biologically pre-programmed to form attachments with others, because this will help them survive. The infant produces innate behaviors such as crying and smiling that stimulate innate nurturing responses from adults. The determining factor of attachment is not food but care and responsiveness. This theory also suggests that there is a critical period for attachment development. If an attachment is not established during this critical period, the child will suffer irreversible developmental consequences, such as reduced intelligence and increased aggression. Ainsworth (1965) defines attachment as: An affective bond that a person or animal forms between itself and a specific other – a bond that unites them in space and lasts over time. Attachment is not just a connection between two people; it is a bond that involves the desire for regular contact with that person and the experience... middle of paper... or negative. For example, children who have a secure attachment as infants tend to develop stronger self-esteem as they grow up. These children also tend to be more independent, perform better in school, have successful social relationships, and experience less depression and anxiety. While children with other attachment styles may have low self-esteem and experience anxiety, resulting in unsuccessful development, socially and emotionally. In conclusion I have provided an explanation of what attachment theory is and indicated which are the most important psychologists who have explored this idea and how they have studied it. I presented substantial studies that psychologists use to measure attachment between a child and his or her caregiver and revealed their findings about attachment styles that influence an adult's social and emotional development..