In applied behavioral analysis, the Matching Law states that the relative proportion of times an animal will perform a behavior in response to a cue is equal to the proportion of times that animal is reinforced for doing so.
When a behavior is reinforced more often, the animal will choose to perform it more often. Experiments showed that the relative proportion of responses matched the relative proportion of reinforcement almost perfectly. In dog behavior, this means that behaviors that are most often rewarded will be most likely to occur in the future. Behaviors that are consistently rewarded, using a high rate of reinforcement, can be expected to be consistently performed.
Herrnstein R. J. Relative and absolute strength of response as a function of frequency of reinforcement. Journal of the Experimental Analysis of Behavior. 1961;4:267–272.
Reed D.D, Kaplan B.A. The Matching Law: A Tutorial for Practitioners. Behavior Analysis in Practice. 2011;4(2):15-24.