The affection is mainly biological factor. Then further sort of strengthening, that religion helps.
Dalai LamaWith a basic understanding of all humans as brothers and sisters, we can appreciate the usefulness of different systems and ideologies that can accommodate different individuals and groups with different cultural heritages, having different dispositions and tastes. Each person has the right to choose whatever is most suitable, on the basis of a deep understanding of all others as brothers and sisters.
Dalai Lama