“…In consequence, the uncertain state of this literature likely reflects these scientific and methodological disparities (Michalski & Shackelford, 2001; Price & Hare, 1969). For mean level analyses, depending on these parameters, mothers have been reported to favor firstborns (e.g., Belsky, Gilstrap, & Rovine, 1984; Dunn & Plomin, 1986; Hallers-Haalboom et al, 2014; Jacobs & Moss, 1976; van IJzendoorn et al, 2000) or favor secondborns (e.g., Moore, Cohn, & Campbell, 1997; Ward, Vaughn, & Robb, 1988) or treat first- and secondborns equitably (e.g., Dunn & Plomin, 1986; Dunn, Plomin, & Nettles, 1985; Holden & Miller, 1999). By contrast, mothers’ socioemotional interactions with their two children tend to show moderate order consistency (e.g., Dunn & Plomin, 1986; Dunn, Plomin, & Daniels, 1986; Dunn et al, 1985; Robinson & Little, 1994; van IJzendoorn et al, 2000), albeit with some exceptions dictated by moderator.…”