A Miami judge must decide the best option for a 4-year-old girl who is the object of a parental-rights dispute between her biological father and the family that for the past two years has cared for her, and protected her, by concession of the state.

Because of psychological problems and a clear emotional instability, the mother lost the custody of her children shortly after emigrating legally to the United States. The father traveled from Cuba to claim his daughter. He seems to be a good, hardworking person of modest means.

He is of peasant stock and lives in a small town where he raises pigs, goes fishing, and plants fruit trees. He plans to return to the island with the girl and bring her up in his quiet environment, a rural segment of the communist domain where he has lived all his life, apparently with more resignation than enthusiasm, like most of his compatriots.

The folks who have sheltered the girl -- and have already adopted her half-brother by a different father -- also give the impression of being  loving and well-intentioned people. They are educated and enjoy a good economic situation within the capitalist model that the United States leads worldwide.

Poor judge. The decision is not obvious. What seems most reasonable is to turn the girl over to her biological father and bring the litigation to an end. In general principles, children should be raised by their biological parents. That's the logic of nature.

Then come the shadings. Poor peasants have the right to bear children. The people who live (and suffer) under atrocious dictatorships also have a right to bear children. Why deprive of parental rights a person who, according to all external evidence, is a generous father willing to fight to be reunited with a daughter he evidently loves?

But the other side of the drama subtly complicates the legal and moral judgment. The law asks the judge to do something as vague (but just as real)  as to rule in accordance with the child's best interests. In this case, the law places the girl's happiness -- an abstraction -- above the rights of the father --a reality based on biology.

What to do? Although happiness is a subjective concept, common sense indicates that there are situations where the probability of being happy increases or diminishes greatly.

To better understand the issue, let us consider another scenario. Assume the girl's father -- loving, decent and hardworking -- came from Sudan, a nation torn by a horrible civil war, and said he wanted to return with his daughter to his place of origin. Should the father's right to be with his daughter prevail under any and all circumstances? Or should the girl's right to lead a normal childhood in a stable, organized and prosperous society (in which she is beginning to move) prevail?

Let us look at another example that is not at all infrequent. If the girl's father were an honorable Ethiopian who is convinced of the advantages of female genital mutilation, should the judge turn the girl over to him by virtue of the unquestionable rights granted by paternity?

What I mean to say is that if the judge is going to enforce the spirit of the law and if she really takes into account the girl's happiness and subordinates the father's rights to that happiness, she will have to place on the scales all the adjunctive elements that complicate moral judgment: the type of society where the child will live, the material quality of her environment, and the rules that prevail within the group.

Is there an element that indicates whether a type of society generates a greater or lesser degree of happiness? It seems there is. Although international studies on happiness are relatively recent, most of the people surveyed stressed the importance of a key element. Aside from material issues and genetic aspects -- some people are predisposed to being happy or unhappy -- there is a close relationship between the capacity to make decisions that affect us personally and the degree of happiness that we achieve.

In those studies, as in many other aspects, the Scandinavian societies head the list of happy countries. In those nations, and in other First-World democracies, people have a much greater control over their lives. Conversely, in totalitarian societies, the outlook is totally different.

In sum: poor girl, poor biological parents, poor foster parents, and poor judge. There are circumstances where everybody loses.