“…Relative to the number of studies conducted on friendship in older children (Fink, Begeer, Peterson, Slaughter, & Rosnay, 2015), or on young children's non-peer relationships such as mother-child relationships (Engdahl, 2012), there have been few studies on friendship in very young children (van Hoogdalem et al, 2013). Barron (2011) suggests that this may be due to the influence of Jean Piaget's work, which regarded young children as "egocentric and their friendships as unstable, and, therefore, seemingly unworthy of study" (Barron, 2011, p. 658). Based on Piaget's theory, friendship has been viewed as a development stage that depends on children's ability to have 'theory of mind' or understanding of perspective-taking, which do not develop until children are around age three (Hay et al, 2004).…”