The Florida district court of appeals last week heard arguments on a case challenging the state's gay adoption ban. The state said that the ban is justified because gay couples are more prone to domestic violence, psychiatric disorders, and breakups.

These arguments may sound familiar–they are the same ones used by opponents of same sex marriage. In particular, gay marriage opponents say that higher rates of separation in gay relationships threaten marriage as an institution.

Self-Fulfilling Prophecy

But the arguments against gay marriage only perpetuate the statistics against same sex couples. The inability for gay couples to get married increases the risk of domestic violence and breakups, the same aspects used to deny them marriage in the first place.

Unable to get married in most of the country, gay couples are stuck in an endless state of cohabitation. And as Fox News reported in July, a study published in the Journal of Family Psychology this year showed that cohabitation without getting married creates commitment problems:

Those who moved in with a mate before engagement or marriage reported significantly lower quality marriages and a greater potential for split-ups than other couples.

While this study is recent, the downsides of cohabitation have long been documented. Research consistently shows that cohabitation relationships lead to increased domestic violence, infidelity, and financial strife.

Because gay couples can't marry in most states, the most they can usually do is live together. Even when their state, through domestic partnership laws, gives them some marital rights, the lack of a full union still makes their relationship a glorified cohabitation.

As a result, Florida has created the very circumstances it uses to justify its gay adoption ban. The state has (1) put a ceiling of cohabitation on gay relationships and now (2) argues that the effects of this ceiling mean that gay couples shouldn't adopt.

[Cross-posted at the Gay Couples Law Blog, which discusses same sex family law and estate planning.]