Five studies investigated (a) children’s ability to use the dependent and independent probabilities of events to make causal inferences and (b) the interaction between such inferences and domain-specific knowledge. In Experiment 1, preschoolers used patterns of dependence and independence to make accurate causal inferences in the domains of biology and psychology. Experiment 2 replicated the results in the domain of biology with a more complex pattern of conditional dependencies. In Experiment 3, children used evidence about patterns of dependence and independence to craft novel interventions across domains. In Experiments 4 and 5, children’s sensitivity to patterns of dependence was pitted against their domain-specific knowledge. Children used conditional probabilities to make accurate causal inferences even when asked to violate domain boundaries. The past two decades of research have demonstrated that young children understand cause and effect in a wide range of contexts. By the age of 4, children’s folk physics includes knowledge about the causal relationship between object properties and object motion

nt to extinction. The persistence of responding on the timeout lever after avoidance extinction is not readily explained by current theories. Key words: avoidance, extinction, timeout, negative reinforcement, lever press, rats Avoidance responding can be highly resistant to extinction in certain situations; this observation has been used to help explain clinical phenomena such as phobia and obsessive -compulsive disorder (Levis, 1991; Stampfl, 1987). However, the situations in which great resistance to extinction of avoidance has been noted have usually involved discrete-trial procedures with running or jumping as the response (see Solomon & Wynne, 1954). Lever-press shock-postponement schedules such as Sidman's (1953) procedure generally result in behavior that declines fairly rapidly when shock is removed (e.g., Shnidman, 1968). Such outcomes have been interpreted as supporting theories that lever-press avoidance in the rat has a special This resear