Stanton v. Stanton, 421 U.S. 7 (1975), is a United States Supreme Court case which struck down Utah's definitions of adulthood as a violation of equal protection: females reached adulthood at 18; males at 21.

[1]: 218  Utah divorce court ruled against the mother, and the Utah Supreme Court held that there was a "reasonable basis" for the differential: women matured earlier and married younger; men had a greater need for education.

[1]: 218  The Utah court stated in its opinion that the basis for the law, though an "old notion," was not unconstitutional.

[1]: 218 The Stanton decision placed the Court on record as declaring that society's stereotypes were not a legitimate basis for official policies that treated men and women differently.

If a specified age of minority is required for the boy in order to assure him parental support while he attains his education and training, so, too, is it for the girl.