siblings set their first horizontal relationships, providing a preparation for the social context adaptation. According to Dunn (1983), sibling relationships are formed and strengthened in childhood, which is the period in which siblings spend more time together, influencing themselves reciprocally and decisively. In adolescence, siblings undergo major changes and experiences that cause a normalized distance, as young people leave home and create new extra-familial relationships, particularly with pairs or loving figures. In adulthood, and especially in old age, after children leave home and/or individuals become widowed, siblings may return together, and became the mainstay in this phase of life. Siblings allow the sharing of experiences, affection, support, guidance and mutual protection, as well as it enables the development of intimacy (Fernandes 2005). Button and Gealt (2010) also indicate that healthy sibling relationships support the growth of social, cognitive and emotional skills, which lead to positive and healthy results. Volling (2003), however, argues that sibling relationships may favor or condition emotional and social development of individuals, both in childhood and in adolescence. Fernandes, in 2002, clarifies that, in fact, besides the positive feelings that exist between siblings, it may also arise a great destructive potential within that relationship of deep intimacy. In this sense, when the interactions between siblings are ruled by conflicts, being conducted by a negative interaction, they may give rise to the manifestation of maladaptive or even violent behaviors (Goldsmid and Féres-Carneiro 2007).