An attachment bond, as defined by Rudolph Schaffer, is a long-lasting, emotionally significant relationship with a specific person. In the past, therefore, attachment research and studies have only been applied to monogamy; nowadays, however, there is a sizeable group of non-monogamous people who enjoy secure, loving, and healthy relationships with multiple partners, and the insights these studies can provide about the human connection and the bonds created by non-monogamous people is not insignificant.
Just to reiterate, the attachment bond is a long, emotionally important relationship defined as connecting us to a specific person. According to the British psychologist John Bowlby, father of the so-called "attachment theory", a child is born with a real biological predisposition to develop an attachment for those who take care of them: the attachment would have the biological function of protecting the child and the psychological function of providing security (John Bowlby, 1983). There are several studies that underline the strong impact that the quality of this bond has on the future development of the child, on their cognitive abilities, brain development, mental health and on the correct formation of future social relationships.
Furthermore, attachment affects a person’s choice of partner and their ability to organise their emotional life: already from early childhood, we observe and learn models of representation of self and of the other, which we then tend to apply throughout the course of our life.
As children, we need to know that adults will provide us with a safe haven when we need it, a belief that gives us a secure foundation from which we can explore our surroundings. John Bowlby calls this concept the "exploratory behavioural system." What's remarkable is that when our attachment needs are met, this system allows us to feel comfortable and free to explore ourselves, others, and the world around us. Research by John Bowlby and Mary Ainsworth shows that children develop more secure or more insecure attachment styles depending on how well their parents are able to provide a dependable, accessible and responsive haven for them.
In other words, if our "attachment figures" were absent or changeable when we were children, our ability to freely explore and learn about the world and ourselves will have been stunted, or at least inhibited. When this happens, as adults we develop alternative strategies for interacting with others: thus, we have adults who are always on high alert or who display anxious behaviour, or - even worse – are "avoidant" and contemptuous.