We evaluated the effects of 2 types of training on the emergence of bidirectional intraverbal relations with 4 typically developing children. Tact training involved reinforcing foreign-language vocalizations in the presence of visual stimuli, and listener training involved reinforcing selections of visual stimuli following vocal presentations of…

The authors investigated how 3- and 4-year-old children and adults use relative distance to judge nearbyness. Participants judged whether several blocks were by a landmark. The absolute and relative distance of the blocks from the landmark varied. In Experiment 1, judgments of nearbyness decreased as the distance from the landmark increased, …