Saying that children are human beings with universal human rights seems like a logical, obvious, irrefutable and incontestable statement. However, in practice, that seems not so logical for many adults both in modern and traditional societies: children are not like adults, so they cannot have the same rights, this is common sense. It is a natural tendency to think about the differences between human groups, rather than the similarities. Many (adults) are concerned about whether the rights recognized to young people and adults should be different, rather than whether they should be the same. In this chapter we will explain how the logics of denying similarities of (the rights of) all human beings is a major contributor to discrimination between human groups—and we will focus our reflections on children and childhood. We will also tempt to explain why adults (unconsciously or not) tend to imagine children as a different social group or category of people. In fact, children (and adolescents, and even youngster) are often thought as the not yet adults and as the other category of human beings (of course, with not yet as good qualities as us) (Verhellen, 1992: Casas, 1996a). This shared images, believes, logics or stereotypes about different social groups or categories of people are named social representations (Moscovici, 1981, 1982; Casas et al., 2014). The dynamics of intergroup categorization easily brings to ideas about the endogroup members having much better qualities than the exogroup members (Tajfel, 1978, 1981; Doise et al., 1980). For that reason, adults may think that children logically are not as competent, responsible, reliable or endowed with rights than adults. Although some historical roots of this thinking are probably overcome in many societies (e.g. the child as a property of the parents), other implications are still difficult even to discuss in non-academic arenas—and in practice bring to the discrimination of children in society, and to deny them the right and opportunity to social participation, despite that right is recognized by the UN Convention on the Rights of the Child.