“…That is, children's formal fraction knowledge may have helped them to encode spatial proportions and to reproduce them on the rating scale. Even though this possibility cannot be eliminated by our correlational results, it seems unlikely in light of many studies (Acredolo et al, 1989;Boyer & Levine, 2012;Boyer et al, 2008;Jeong et al, 2007;Schlottmann, 2001;Singer-Freeman & Goswami, 2001;Sophian, 2000;Spinillo & Bryant, 1991, 1999 showing signs of proportional reasoning at an age when understanding of formal fractions is not present (Hecht & Vagi, 2010;Schneider & Siegler, 2010;Stafylidou & Vosniadou, 2004). Nonetheless, future studies using longitudinal designs or training components are needed to pin down the causal direction of the relation we have identified.…”