“…Finally, it is worth noting that successive-matching-like procedures have also been used in studies of human equivalence-class formation (e.g., Layng & Chase, 2001; Takahashi, Yamamoto, & Noro, 2011; see also Fields, Doran, & Marroquin, 2009). In this literature, the precursor to the Relational Evaluation Procedure (pREP – e.g., Cullinan, Barnes, & Smeets, 1998; Leader & Barnes-Holmes, 2001; Smeets, van Wijngaarden, Barnes-Holmes, & Cullinan, 2004) represents the closest approximation to successive matching procedures used with pigeons.…”