In the interpretation of wills and trusts, adopted persons and persons born out of wedlock are included in class gift terminology or terms of relationship in accordance with rules for determining relationships for purposes of intestate succession unless a contrary intent appears on the face of the will or trust. In determining the intent of a testator or settlor, adopted persons are presumptively included in such terms as “children,” “issue,” “kindred,” “heirs,” “relatives,” “descendents” or similar words of classification and are presumptively excluded by such terms as “natural children,” “issue of the body,” “blood kindred,” “heirs of the body,” “blood relatives,” “descendents of the body” or similar words of classification. In the event that a fiduciary makes payment to members of a class to the exclusion of persons born out of wedlock of whose claim of paternity or maternity the fiduciary has no knowledge, the fiduciary shall not be held liable to such persons for payments made prior to knowledge of such claim. This section shall apply to all inter vivos trusts executed after July 1, 1978, and to all wills of decedents dying after July 1, 1978, regardless of when executed.