Thomas Dietz reassesses Robert Cialdini's revolutionary treatise on the science of decision-making.
Influence: The Psychology of Persuasion
- Robert B. Cialdini
We make decisions based on narrow self-interest, calculated benefits, costs and risks. Or so claimed economist Adam Smith, whose 'rational actor model', from his 1776 opus The Wealth of Nations, has long dominated thinking in economics and social science. By the late twentieth century, Smith's view had been applied to every domain of human decision-making, from marriage to international negotiations. But a growing body of evidence began to indicate that the model was often misleading.
Robert Cialdini's 1984 book Influence moved scientific thinking forward by showing that decision-making was messy. Whereas Smith's concept was logical and easy to describe mathematically, Cialdini grasped that decision-making is so complex that no single model can capture it. Analysing the literature on how we make decisions, he offered a picture that is more than a survey of specific research results, yet not quite an overarching unitary theory. The resulting treatise led Cialdini to become one of the most cited social psychologists; his books have sold more than two million copies.
Cialdini saw that Smith's model of rational decision-makers, immune to any influence other than information, was simplistic. In reality, we are bombarded by efforts to persuade us to make decisions that serve the persuader's interests. If we make decisions based on pure logic, why would companies spend billions on advertising? Why would salespeople do more than list prices and options? Why would politicians focus so intently on symbolic messages?
These groups use our decision-making vulnerabilities as a fulcrum. Most people, most of the time, use shortcuts to choose between options — including being swayed by emotions, symbols and norms. This saves time and effort, and Cialdini argued that the shortcuts usually serve us well. But they can lead us badly astray, especially when manipulated by unscrupulous agents. Influence was intended to be a remedy against such manipulation — which Cialdini called the “real treachery, and the thing we cannot tolerate”.
Cialdini articulated six “weapons of influence” — shortcuts that can be manipulated to shape our decisions. These comprise our tendency to reciprocate small favours with larger ones; to stick with commitments and be consistent; to believe what others believe; to go along with what is suggested by those we like; to believe in authority; and to value things that seem scarce. For example, salespeople often start with a desirable offer to get a commitment, then throw in something for free to invoke reciprocity. They will look for clues about the hobbies and interests of customers (to seem likeable) and emphasize the popularity and scarcity of a product to make it seem more desirable.
Cialdini's use of the terms “weapons” and “treachery” reflects his belief that people and communities can suffer when salespeople, multinational corporations or governments work to shape our choices to their advantage. The power and authenticity of Cialdini's book comes in large part from the fieldwork that complements the experimental evidence. He engaged with salespeople, recruiters, marketing people, staff at consumer agencies and others whose jobs are to persuade us or to uncover abuses of persuasion. He even went on sales-training courses to learn how our vulnerabilities can be exploited. These anecdotes make for an engaging read while underlining that persuasive ability is a form of power, often used in destructive ways.
Influence made the nuances of decision-making accessible to a broad audience, and research in that field has since flourished. Neologisms such as 'behavioural economics' and 'neuro-economics' attest to the growing acceptance that the rational actor model is insufficient to describe how we make choices. Four Nobel prizes in economics (to Herbert Simon, Daniel Kahneman, Vernon Smith and Elinor Ostrom, Smith being the sole economist) have been awarded for work that, similar to Cialdini's, pushes beyond that model.
Mainstream policy analysis still relies heavily on the assumption of a rational decision-maker, but social psychology is starting to affect how policies are designed. In the 2008 book Nudge (very much a descendant of Influence), authors Richard Thaler and Cass Sunstein argue that insights from the social sciences — such as our strong tendency to choose the default option no matter what it is — can be used to encourage better decisions.
Thaler and Sunstein call for “libertarian paternalism”, an approach in which everyone should be free to make choices, but which uses the principles of social psychology to push us towards options that are in our best interests. Their optimistic tone contrasts with Cialdini's concern with the effects of “compliance professionals”, who design sales and marketing campaigns and who manipulate us against our own interests. But the scientific core is much the same.
Social psychologists are showing that, to address environmental problems — including huge challenges such as climate change — we will have to acknowledge that humanity does not always behave rationally. This is easy to see: households and organizations waste far more energy and emit far more greenhouse gases than they would if they were strictly rational, for example.
Understanding how individuals and organizations make decisions can suggest ways to close this energy-efficiency gap and significantly reduce emissions, as well as how to handle other environmental issues effectively. The influence of Influence will continue as we incorporate ideas that complement the traditional economic view into science and into policy approaches. Cialdini's legacy is a key starting point for many of us who work on these issues.