In this framework, several longitudinal studies have shown that the IWMs remain quite
stable during the lifespan (Stern, 1985; Tronick and Gianino, 1986; Beebe and Lachmann, 1994; Beebe et al., 1997; Hamilton, 2000; Waters et al., 2000; Steele et al., 2003; Weinfield et al., 2004; Sroufe, 2005).