Abstract
In order to introduce a new way of understanding human speech, the article connects two independent lines of Skinner’s research: his work on verbal behavior and on connecting behavior analysis to evolution. The article discusses an empirical study as an example motivated by this connection. Similar to biologists’ suggestion that natural selection can operate on multiple nested levels, Baum (The Behavior Analyst, 36(2), 283–293, 2013) argues that operant behavior is best understood in terms of nested units. Because verbal behavior is operant behavior, Baum’s view should apply to verbal behavior. We conducted the first experiment designed to explore empirical implications of applying this framework. Six pairs of native Norwegian speaking participants communicated verbally while solving a puzzle task together. We investigated if verbal signals occurred to aid navigation between nested levels of the task. 25,191 words were transcribed, revealing that “Ok” was most frequently spoken at the start of the whole activity with a decreasing trend when starting the description of lower-level units, whereas “Også” / “Og så” (“and” / “and well”) became more frequent as the level of activity decreased. “Ja” (“yes”) most frequently concluded all activity levels. These findings can benefit future studies aiming at experimentally manipulating the verbal stimuli found to guide movement between activity levels. The conceptual argument and empirical example are spelled out to inspire further refinements of the connection between verbal behavior and evolution.