considered that infertility can only be referred to as a disability under certain conditions and presumptions and, thus, only in determined cases, 452 expert witness Paul Hunt observed that “involuntary infertility is a disability,” 453 considering that: “The Preamble to the Convention on the Rights of Persons with Disabilities, to which Costa Rica is a party, recognizes that ‘disability is an evolving concept and that disability results from the interaction between persons with impairments and attitudinal and environmental barriers that hinder their full and effective participation in society on an equal basis with others.’ According to the WHO biopsychosocial model on disability, this entails one or more of the three levels of difficulty in human functions: a physical-psychological impairment; a limitation of activity owing to an impairment (activity limitation), and a participation restriction owing to an activity limitation. According to the WHO International Classification of Functioning, Disability and Health, impairments are problems in body functions; activity limitations are difficulties an individual may have in executing activities, and participation restrictions are problems an individual may experience in involvement in life situations.” 454 290. Article 18 of the Additional Protocol to the American Convention in the Area of Economic, Social and Cultural Rights (“Protocol of San Salvador”) states that “[e]veryone affected by a diminution of his physical or mental capacities is entitled to receive special attention designed to help him achieve the greatest possible development of his personality.” The Inter-American Convention for the Elimination of all Forms of Discrimination against Persons with Disabilities (hereinafter “ICEFDPD”) defines the term “disability” as “a physical, mental or sensory impairment, whether permanent or temporary, that limits the capacity to perform one or more essential activities of daily life, and which can be caused or aggravated by the economic and social environment.” For its part the, the CRPD establishes that “persons with disabilities include those who have long-term physical, mental, intellectual or sensory impairments which in interaction with various barriers may hinder their full and effective participation in society on an equal basis with others.” The disability results from the interaction between an individual’s functional limitations and the barriers that exist in the environment that prevent the full exercise of his rights and freedoms. 455 291. The above-mentioned Conventions take into account the social model in their approach to disabilities, which means that the disability is not defined exclusively by the presence of a physical, mental, intellectual or sensorial impairment, but that it is interrelated to the barriers or limitations that exist in society for the individual to be able to exercise his rights effectively. 456 The types of limits or barriers that are commonly encountered in society by individuals with functional diversity include those that are attitudinal 457 or socio-economic. 458 452 Opinion provide by expert witness Anthony Caruso at the public hearing held in this case. 453 Affidavit provided by expert witness Paul Hunt (merits report, volume VI, folio 2650). 454 Affidavit of expert witness Paul Hunt, folio 2650. 455 The Preamble of the CRPD recognizes that disability is an evolving concept and that disability results from the interaction between persons with impairments and attitudinal and environmental barriers that hinders their full and effective participation in society on an equal basis with others.” 456 Case of Furlan and family v. Argentina, para. 133. 457 Case of Furlan and family v. Argentina, para. 133. Cf. UN General Assembly, ONU, Standard rules on the equalization of opportunities for persons with disabilities, GA/RES/48/96, 4 March 1994, forty-eighth session, para. 3 (“In the disability field, however, there are also many specific circumstances that have influenced the living conditions of persons with disabilities. Ignorance, neglect, superstition and fear are social factors that throughout the history of disability have isolated persons with disabilities and delayed their development”). 458 Cf. Case of Ximenes Lopes v. Brazil. Merits, reparations and costs. Judgment of July 4, 2006. Series C No. 149, para. 104, and Case of Furlan and family v. Argentina, para. 133. Cf. also Article III.2 of the Inter-American Convention for the Elimination of All Forms of Discrimination against Persons with Disabilities, and Committee on Economic, Social and Cultural Rights, General Comment No. 5, Persons with Disabilities, U.N. Doc. E/C.12/1994/13 (1994), 12 September 1994, para. 9.