How people mentally represent order and equivalence
Recent work by Ulrich von Hecker (Cardiff University) and colleagues investigated the impact of relational semantics on mental models and their structural properties. Their studies reveal a reversal of the symbolic distance effect (SDE), which typically indicates faster and more accurate responses with increasing distance between elements in a mentally constructed rank order. The authors replicated the SDE when relations expressed a rank hierarchy (“older than”), but in cases where the relation signified equivalence classes (“is from the same city”), they observed a reversal of the effect. The research was published in the Quarterly Journal of Experimental Psychology; the abstract is available here:
With mental models based on relational information, the present research shows that the semantics expressed by the relation can determine the structural properties of the constructed model. In particular, we demonstrate a reversal of the classical, well-replicated symbolic distance effect (SDE), as a function of relational semantics. The classical SDE shows that responses are more accurate, and faster, the wider the distance between queried elements on a mentally constructed rank order. We replicate this effect in a study using a relation that expresses a rank hierarchy (“older than,” Experiment 4). In contrast, we obtain a clear reversal of the same effect for accuracy data when the relation expresses a number of equivalence classes (“is from the same city,” Experiments 1–3). In Experiment 3, we find clear evidence of a reversed SDE for accuracy and latency in the above standard condition, and flat curves of means, across pair distances, for accuracy and latency in a condition that makes equivalence classes salient from the beginning. We discuss these findings in the context of a process model of equivalence class formation based on learned piecemeal information.