In the reading (pg 404-405), the child's relationship to the caregiver is what is emphasized. If the child has a good relationship, then they are provided with an good internal working model of the social world. The caregiver, though, may not be the only person of significant impact on the child. For example, the child could have an insensitive caregiver, but a very sensitive older sibling. This relationship with the older sibling can lead the child to form good relationships in the future, despite having a not-so-great caregiver.
i've never thought of that before. using a sibling as a substitute for a neglectful parent is really interesting and probably true. This can therefore be applied to anyone who is seen to the child as a caregiver or or support system such as a cousin, friend, or distant family member. A good question to ask is does age matter? Could a person who has established a relationship with someone younger than he or she still have a healthy well-being later on in life?