ABSTRACT
Communication is an integral part of teaching. Many factors influence whether students comprehend and learn from instructional communication, including whether students have a shared understanding of the referents used by the teacher (Mortimer & Wertsch, 2003), and whether the ideas addressed in a lesson connect to students' prior knowledge (Schwartz & Bransford, 1998). Another potentially important factor that has received limited research attention is the nonverbal support for comprehension provided by teachers' gestures. Gestures are movements of the hands and body that are produced in the act of speaking and that are closely synchronized with speech (McNeill, 1992). Gestures include pointing movements that indicate objects or locations, depictive movements that illustrate the content of speakers' thoughts, and rhythmic movements that mirror the cadence of speech.
