Last week the Supreme Court failed to recognize a rich history of same-sex marriage traditions both abroad and in North America. By drawing on inaccurate information regarding the history of marital practices, the court risks coming to an irresponsible decision on the legality of same-sex marriage bans.

How new is the concept of same-sex marriage? Did it exist in any cultures before 2001 in the Netherlands? These are questions asked by Justices Antonin Scalia and Samuel Alito in last week's debates. Scalia implied that heterosexual marriage was the only accepted pattern "for millennia."

Lawyer Mary Bonauto — although arguing against same-sex bans — fumbled her response. Without receiving a thorough answer, Scalia concluded that no society had ever had same-sex marriage before 2001.

As a professor of cross-cultural psychology, I found Scalia's conclusion deeply frustrating. The problem is not that he acknowledged an uncomfortable truth. Rather, he was completely wrong.

The justices correctly acknowledged that male homosexuality was accepted in some contexts in ancient Greece — in which older males had sexual relationships with adolescent boys — but that same-sex marriages were not allowed. What they did not recognize was that strikingly similar same-sex relationships were once given marital rights in the Azande society of Sudan.

Before the arrival of European colonialists, Azande bachelors regularly married adolescent boys. The marriages were arranged in the same way they were with young women. The bachelors paid a bridewealth to the young man's family, just as they would for a female spouse. The young men took on the same roles as a young wife would. They were expected to behave in a modest manner, to cook for their husbands, and to perform female housework. Just as in ancient Greece, these unions would eventually end as both members aged.

What distinguishes the Azande case from the Greek case, which Alito found interesting, is the formalization of the same-sex relationship in marriage. However, we do not have to look so far from home to find same-sex marriages. Before the arrival of Europeans to North America, many Native American groups acknowledged a third gender — two-spirits people — and their marriages.

Two-spirits people were found in more than 100 Native American cultures — including the Iroquois, Navajo, and Crow — throughout what is now the continental United States. Rather than being classified as either female or male, two-spirits people were regarded as a distinct third gender. Although there was individual variation, typically biologically male two-spirits dressed in women's clothes and engaged in women's work. Likewise, a biologically female two-spirits would often dress in male clothing, carry weapons, and hunt.

Two-spirits people were usually thought to be spirituality gifted and they took on special roles in several cultures. For instance, among the Teton Dakota, they handled naming rituals and worked as diviners.

Societal acceptance of two-spirits people included the right to marry individuals who shared their biological sex. Among the Hidatsa, two-spirits could also complete their families by adopting children. These two-spirits households were often prosperous. Because of their important roles in rituals, and because they were thought to be particularly gifted craftspeople, two-spirits had many opportunities to acquire wealth and status.

It wasn't until the arrival of European colonialists that the two-spirits people came to be viewed in a negative light. Native Americans were pressured to discontinue the tradition that colonialists viewed as shameful. The number of individuals identifying as two-spirits people dramatically decreased and they eventually lost their formal recognition.

Bonauto's failure to include the Azande and two-spirit people in her discussion of the history of same-sex marriage is not surprising. The court's debates have repeatedly failed to consider the vast cross-cultural literature on diverse marital practices. But let the record now be corrected:

Heterosexual marriage is not the only form of marriage that has been recognized in the last millennium. To the contrary, in only the last few hundred years there was a thriving same-sex marital practice in the very land over which the Supreme Court now presides.

Mariah Schug is an assistant professor specializing in cross-cultural psychology at Widener University in Chester.