“…Reports on attachment behaviour in children are widely known (Ainsworth, 1967(Ainsworth, -1982Ainsworth, et al, 1978;Bowlby, 1969Bowlby, -1973Bowlby, -1980Hinde, 1982;Parkes & Stevenson-Hinde, 1982;Bretherton, 1987Bretherton, -1992Cassibba & D'Odorico, 2000). Some articles on the same topic in monkeys have also been published (Harlow, et al, 1962(Harlow, et al, -1966(Harlow, et al, -1969Mason, 1963Mason, -1968Rosenblum, 1971;Tartabini & Simpson, 1986-1987Simpson & Tartabini, 1992;Suomi, 2005;Warfield, et al, 2011). These last publications are mostly concentrated on the effect of the attachment after mother's separation and the method of investigation is the ethological observation with the use of time-sampling, and rating of behaviours (Martin & Bateson, 1986;Suen & Ary, 1989).…”