In studying problem solving behavior in kittens, Thorndike used which term to describe behaviors they displayed to escape an enclosure by pulling a string on a latch?

The answer is Instrumental behavior. It is an action performed to reach a goal, such as to obtain a food item, achieve some other kind of reward, or remove a punishment; the behavior causes the desired outcome. Problem-solving is a subset of instrumental behavior, invoked when a direct action (such as reaching for an object) cannot achieve the goal and an indirect approach must be used (such as opening a container to get the object). To paraphrase Thorndike, a problem exists when the goal that is sought is not directly attainable by the performance of a simple act available in the animal's repertoire.