Social loneliness, emotional balance, and dispositional optimism in elderly people living or not in institutions in the city of Bogotá. Iván Fernando Amaya Cocunubo, Luz Helena Gómez Verano, Nahyr Remolina de Cleves, Bertha Marlene Velásquez Burgos, Lola Rosalía Saavedra Guzmán (Author)