(1) In computing the degrees of relationship between any two (2) kinsmen who are not related in a direct line of ascent or descent, it is proper to start with the common ancestor of the kinsmen and count downwards. In whatever degree the kinsmen or the more remote of them is distant from the common ancestor, that is the degree in which they are related to each other.
(2) Thus two (2) or more children of a common parent are related to each other in the first degree, because from the common parent to each of the children is counted only one (1) degree.
(3) But a person and his or her nephew are related in the second degree, for the nephew is two (2) degrees removed from his grandparent who is the common ancestor.
(4) A person and his or her second cousin are related in the third degree, for they are both three (3) degrees removed from the great-grandparent who is their common ancestor.
(5) In computing the degrees of relationship between any two (2) kinsmen related in a direct line of ascent or descent, the degree of relationship shall be determined by starting with one (1) of the persons and counting up or down to the other. Thus, a person and his or her: Parent or child are related in the first degree;
(6) Grandparent or grandchild are related in the second degree; and
(7) Great-grandparent or great-grandchild are related in the third degree.