Why do our headaches persist after taking a one-cent aspirin but disappear when we take a 50-cent aspirin? Why does recalling the Ten Commandments reduce our tendency to lie, even when we couldn't possibly be caught? Why do we splurge on a lavish meal but cut coupons to save twenty-five cents on a can of soup? Why do we go back for second helpings at the unlimited buffet, even when our stomachs are already full? And how did we ever start spending $4.15 on a cup of coffee when, just a few years ago, we used to pay less than a dollar? When it comes to making decisions in our lives, we think we're in control. We think we're making smart, rational choices. But are we? In a series of illuminating, often surprising experiments, MIT behavioral economist Dan Ariely refutes the common assumption that we behave in fundamentally rational ways. Blending everyday experience with groundbreaking research, Ariely explains how expectations, emotions, social norms, and other invisible, seemingly illogical forces skew our reasoning abilities. Not only do we make astonishingly simple mistakes every day, but we make the same types of mistakes, Ariely discovers. We consistently overpay, underestimate, and procrastinate. We fail to understand the profound effects of our emotions on what we want, and we overvalue what we already own. Yet these misguided behaviors are neither random nor senseless. They're systematic and predictable—making us predictably irrational. From drinking coffee to losing weight, from buying a car to choosing a romantic partner, Ariely explains how to break through these systematic patterns of thought to make better decisions. Predictably Irrational will change the way we interact with the world—one small decision at a time.

丹·艾瑞裏，18歲時的一場爆炸意外，讓艾瑞裏全身皮膚70％灼傷，住在燒傷病房達三年之久。身穿治療用黑色彈性緊身衣、頭戴麵罩的他，自嘲為“蜘蛛俠”。但恰恰是在這段漫長、無聊，而又痛苦不堪的歲月裏，那套奇異的“蜘蛛俠”服裝拉開瞭他與外界的距離，使他可以以局外人的眼光重新看待身邊的世界，從此有瞭探索人類行為與經濟關係的興趣。最終，他成為著名行為經濟學傢。

丹·艾瑞裏是美國麻省理工學院傳媒實驗室艾爾弗雷德·P·斯隆基金會和斯隆管理學院行為經濟學教授、波士頓聯邦儲備銀行研究員、普林斯頓高等研究中心研究員。在麻省理工學院期間他寫瞭這部行為經濟學的重要著作。他的文章一直在重要的學術期刊，以及《紐約時報》和《華爾街日報》的專欄上發錶。