Background Paragraph: The example of someone having a positive experience with a drug is easy to see how drug dependence and the law of effect works. The tolerance for a drug goes up as one continues to use it after having a positive experience with a certain amount the first time.[38] It will take more and more to get that same feeling. This is when the controlled substance in an experiment would have to be modified and the experiment would really begin. The law of work for psychologist B. F. Skinner almost half a century later on the principles of operant conditioning, "a learning process by which the effect, or consequence, of a response influences the future rate of production of that response.[39]. 
Story: The Smack Squad met to discuss their experiences. They all said they always had a great experience using smack and used the same amount each time. They told how many times they used smack. Joyce used it 17 times, Diane used it 23 times, Alice used it 27 times, Julie used it 35 times, Heather used it 43 times, Teresa used it 54 times, and Doris used it 65 times. 
Question: Who has a higher tolerance for smack: Joyce or Doris?
Doris.