interests before the well-being of her daughters (supra para. ¡Error! No se encuentra el origen de la referencia.), and ii) that “in the context of a heterosexual and traditional society” the father offered “more favorable arguments on behalf of the girls’ best interests” (supra para. ¡Error! No se encuentra el origen de la referencia.). In this regard, the Court considers that, as with the judgment of the Supreme Court (supra para. 97), the provisional custody decision was based mainly on Ms. Atala’s sexual orientation. Therefore, this Court concludes that there was a difference in treatment based on this category. 99. To determine whether these differences in treatment constituted discrimination, the following paragraphs analyze the justification given by the State for making such a distinction in treatment, in other words, the supposed protection of the child’s best interest and the alleged damage the girls had suffered as a consequence of their mother’s sexual orientation. 4. The principle of the child’s best interest and assumptions of risk Arguments of the parties 100. The Commission considered that a child’s best interest is “not only a legitimate aim, but also a pressing social need,” but that “the lack of suitability or causal relationship between the goal sought and the distinction [made]” is evident in the speculative and abstract reasoning of the decisions.” 101. The Commission stated that “both judicial authorities [(the Supreme Court and the Juvenile Court of Villarrica)] based their decisions on assumptions of risk derived from prejudices and erroneous stereotypes regarding the characteristics and behavior of a given social group.” In this regard, it argued that “the decision was based on the judges’ stereotyped conceptions of the nature and effects of relationships between people of the same sex.” 102. The representatives argued that the girls’ best interest “would in fact, in theory […] be a legitimate goal.” However, they stated that “it is not enough […] to argue a legitimate goal for it to be one; the State has the obligation to prove that said goal is real.” In this regard, they argued that “the State simply says it is protecting the girls but it does not objectively offer grounds for the damage that was allegedly caused to the girls and, therefore, the decision lacks a legitimate goal.” 103. The representatives also stated that “it is appropriate to consider whether complete separation from the mother fulfills the stated objective of protecting the girls.” In this regard, they argued that “it may be considered that it does, even though it does so a way that does not satisfy the principle of prohibition of arbitrariness, since the level of intensity with which the rights are affected is clearly very high, and this leads to violations of their rights.” Specifically, the representatives indicated that the court decisions “separate[d] the girls from their mother figure, their referent, their place of residence, schools, friends, and pets.” Furthermore, the representatives noted that the State “rewrites the judgment it would have wished the Supreme Court to write, but it is not the one that began this proceeding.” parameters – as is the merits of the proceedings – and to a judgment of probability, deciding in an interlocutory manner due to the urgency the well-being of the girls calls for, with which of the two parents it is convenient that they stay.” Ruling in the provisional custody claim by the Juvenile Court of Villarica, May 2, 2003 (record of appendices to the claim, volume V, pages 2559 to 2567). 36