predictably irrational the hidden forces that shape our decisions

People also overvalue their belongings and fear giving them up, believing they will lose the memories and experiences associated with those belongings. The desire for short-term gains over long-term benefits (procrastination) leads a person to save less, check email too frequently, rush to complete assignments, fail to get health exams on a regular basis, and so on. Not only do people act differently in these high emotional states, but, when they are not in these states, they also fail to predict how such emotions will influence them.Ĭhapters 7 through 9 focus on the costs of predictably irrational behaviors. Emotionally piqued states also trample social norms. For example, when offered free homemade cookies at work, a person will take one or two, knowing that colleagues might want some-however, if a coworker asks if someone wants to purchase these cookies, that person will take many more people become selfish when money is introduced into social exchanges. Mixing these norms yields unexpected negative results and often damages social relationships.Ĭhapters 5 and 6 explore how financial transactions and high emotional states disrupt social norms, or the unwritten rules that help people navigate social interactions. Chapter 4 addresses something even more troublesome: when people insert money into situations that operate under social rather than market norms the former norms require no money, while the latter do.

Gravitating toward a FREE! item is not inherently bad, but it becomes irrational when someone picks the FREE! item over a better option (such as choosing a free $10 gift certificate over a $20 gift certificate for seven dollars). Despite humans’ desire for rational decisions, many decisions stem from first impressions and gut feelings.Ĭhapter 3 highlights that humans also get an emotional charge from FREE! items, regardless of whether those items are products or money. He then expands on the idea of relativity, presenting evidence for how humans anchor to initial prices and use these first impressions as a reference point for future similar items this influences subsequent decisions (an idea known as arbitrary coherence). Ariely suggests people’s decisions are based on an item’s comparability-or relativity-to other items. Chapters 1 and 2 explore one such influence: the human lack of an internal meter for evaluating an item’s worth.

The latter edition is the basis for this guide.įollowing the Introduction, Ariely details the various influences on human behavior as well as how a person might overcome some of these forces. While the book was originally written in 2008, Ariely published a revised and expanded edition in 2010 with Harper Perennial.

Predictably irrational the hidden forces that shape our decisions