Mason v. Dwinnell, decided yesterday, upheld a trial court's decision that awarded joint custody of a child to the biological mother (Dwinnell) and the mother's lesbian ex-partner (Mason). The child had been conceived when Mason and Dwinnell were a couple, and was raised by Mason and Dwinnell together until the two broke up when the child was four; the two had then, by mutual agreement, had joint custody until the child was seven.

The court stressed that "[a]lthough this appeal arises in the context of a same-sex domestic partnership, it involves only the constitutional standards applicable to all custody disputes between legal parents and third parties." And the court reasoned -- applying what looks like the "psychological parent" doctrine that quite a few courts have applied in recent years -- that because Dwinnell voluntarily let Mason help raise the child for several years, and let the child treat Mason as a parent, Dwinnell voluntarily surrendered her constitutional right to exclusive control over the child. The proper standard was thus the "best interests" standard applicable to disputes between parents; and the trial court's decision that joint custody was in the child's best interests was not an abuse of discretion.

I haven't thought much about the psychological parent doctrine, but I'm inclined to think that it is sound. And if it's sound in general -- for instance, when the psychological parent is a stepparent who raised the child from infancy (with the other biological parent out of the picture) -- then it's equally sound for same-sex relationships. Whatever one might say about whether in the abstract it's better for a child to be raised by a woman and a man or by two women, a child who has formed deep emotional bonds with two women deserves the same protection for those bonds as does a child who has formed such bonds with a woman and a man.