Predictably Irrational by Dan Ariely challenges the very thought process using which we make conclusive decisions after pragmatic thinking. This has been supplemented by his research and trials. He also cites several interesting accounts to make the book all the more interesting. The author shows how mistakes made by people are repeated. This eventually teaches a person to change so as to avoid the mistake in the future. There are a total of fifteen chapters that explain the different facets of the thinking process. The chapters under the title The Truth About Relativity state that people relate themselves to things in a manner that is convenient to them. The chapters under the heading The Fallacy of Supply and Demand cites instances where people fall victim to the fact that a certain product is in great demand and therefore rush to acquire it. In the Cost of Free, the author states that people fall into the trap of a product being offered for free and do not see the merits in the product. In Being Paid vs. A Friendly Favor, the book talks about how immediate repayment is not warranted as the lender is befriended. Under the title Emotion in Decision Making, he illustrates how being emotional affects the decision making process in humans. Under The Problem of Procrastination and Self-Control, how anger reverses the decisions that people have decided upon in a cool frame of mind is discussed. Further, in The High Price of Ownership, the author highlights the human tendency to assume that a product becomes more valuable if they own it. In the Effect of Expectations, the experimental findings of how people stereotype things that they anticipate are detailed. Under the last header, The Power of Price, the author presents his findings on the effect of price while selecting medications.