Although responses are sometimes easy to predict, at other times responding seems highly
variable, unpredictable, or even random. The inability to predict is generally attributed to …

Although reinforcement often leads to repetitive, even stereotyped responding, that is not a
necessary outcome. When it depends on variations, reinforcement results in responding that …

How do children acquire the vast array of concepts, strategies, and skills that distinguish the
thinking of infants and toddlers from that of preschoolers, older children, and adolescents? In …

Effective conditioning requires a correlation between the experimenter's definition of a
response and an organism's, but an animal's perception of its behavior differs from ours …

Some studies have found that extinction leaves response structures unaltered; others have
found that response variability is increased. Responding by Long-Evans rats was …

A design that included both microgenetic and cross‐sectional components was used to
examine 135 Slovenian children's acquisition of matrix completion proficiency and compare …

Previous research has demonstrated that behavioral variability can be modified by
reinforcers contingent on it, but there has been no convincing evidence of discriminative …

Reinforcement of variability may help to explain operant learning. Three groups of rats were
reinforced, in different phases, whenever the following target sequences of left (L) and right …

Long-Evans rats were reinforced for generating variable sequences of four left (L) and right
(R) leverpress responses. If the current sequence, for example, LLRR, differed from each of …

The spontaneously hypertensive rat (SHR) may model aspects of human attention deficit
hyperactivity disorder (ADHD). For example, just as responses by children with ADHD tend …