According to Bowlby, "the attachment conceptualized as being a vital and close bond with just one attachment figure," is called: An example of this is a maternal-infant bond, when a mother feels as if she can only bond with one child at a time. For instance, when a mother births twins and brings one home earlier than the other, and later feels less connected to the twin brought home second. The twin brought home second maybe more apt to fail to thrive.