29 EUROPEAN JOURNAL OF BEHAVIOR ANALYSIS NUMBER 1 (SUMMER 2008) 2008, 9, 29 - 42 29 Human performances on schedules of re- inforcement and conditional discrimination tasks have both revealed important inluences of verbal behavior (e.g., Lowe, Beatsy, & Ben- tall, 1983; Matthews, Catania, & Shimof, 1985; Devany, Hayes, & Nelson, 1986; Lowe, Harzem, & Hughes, 1987; Hayes, 1989; Horne & Lowe, 1996; Wulfert, Dougher, & Greenway, 1991; Cabello, Luciano, Gómez, & Barnes-Holmes, 2004). hese experiments increasingly point to interactions between verbal and nonverbal behavior as a critical factor in understanding human behavior but the precise nature of this interaction and the appropriate methods for studying them remain a matter of debate (Shimof, 1986). here are two main approaches to the problem. In the irst, a participant is presented with a task and later asked to introspectively report on how they performed the problem (Critchield & Perone, 1990; Ribes & Martínez, 1990). his approach is correlational, leaving open many questions about whether the post-session verbal behavior was actually occasioned by the nonver- bal behavior or the post-session questionnaire (Shimof, 1986). In the second approach, a participant’s verbal behavior is manipulated like We are grateful for the technical assistance in programming the experiment lent by Carlos Martínez. Questions may be directed to the irst author at, Facultad de Estudios Superiores Izta- cala - Universidad Nacional Autónoma de México, Avenida de los Barrios No 1, Los Reyes Iztacala, Tlalnepantla Estado de México, C.P. 54090. Email: dianam@campus.iztacala.unam.mx Efects of Trial-Speciic Verbal Descriptions on Matching-to-Sample Performances of Children and Adults Diana Moreno, Olivia Tena, Rosa María Larios, María Luisa Cepeda, Hortensia Hickman, Patricia Plancarte, Rosalinda Arroyo Facultad de Estudios Superiores Iztacala - UNAM and Daniel T. Cerutti Duke University Efects of verbal descriptions of stimulus relations on second-order identity matching were evaluated by arranging a sentence-completion requirement prior to matching a comparison to a sample stimulus. Sixteen college students (X=19 years) and 16 elementary school children (X=10 years) participated. hree experimental groups at each age were exposed to variants in the sentence completion format: descriptions of (1) matching contingencies, (2) relevant stimulus dimensions, or (3) choice performance. A control group had no exposure to sentences. Efects of verbal descriptions were evaluated on acquisi- tion and transfer of matching. Across ages, experimental groups demonstrated higher accuracy during training and transfer tests. Between ages, adults matched more accurately than children; only control children never matched above chance. hese indings are discussed in terms of the inluence of verbal behavior on the acquisition and transfer of inductive repertoires in humans. Key words: Stimulus relations, matching-to-sample, second-order identity, inductive learning, transfer, verbal behavior, children, adults, humans.