Attachment in children is "a biological instinct in which proximity to an attachment figure is sought when the child senses or perceives threat or discomfort. Attachment behaviour anticipates a response by the attachment figure which will remove threat or discomfort". Attachment also describes the function of availability, which is the degree to which the authoritative figure is responsive to the child's needs and shares communication with them. Childhood attachment can define characteristics that will shape the child's sense of self, their forms of emotion-regulation, and how they carry out relationships with others. Attachment is found in all mammals to some degree, especially nonhuman primates.