In everyday life, persuasion is a handy skill that can help you secure a good bargain at the market or wriggle your way out of a parking ticket. In the corporate world, persuasion is a multimillion-dollar industry. People who are skilled in persuasion are able to negotiate favorable deals for clients, advocate for promotions, and launch startups by convincing investors to get on board with their cause. Given the conspicuous importance of persuasion, it is no surprise that social psychologists have begun to dissect some of the underlying forces that shape people’s attitudes and behavior when it comes to convincing others. Much of this psychology is premised on the tenet that although we like to believe our decisions to be purely rational and consistent, judgments are often susceptible to situational and emotional forces. As such, research on the psychology of persuasion primarily relies on six principles developed by prominent psychologist Robert Cialdini, and deal with the contextual factors affecting decision-making. This article will cover some key principles of persuasion, imparting practical ways to improve your persuasive skills along with psychological studies that back up these techniques.

Reciprocity

            The first tenet, Reciprocity, underlies key aspects of persuasion and refers to the simple principle that people generally feel obligated to pay back others in exchange for what they have received. Reciprocity is evident in the unspoken, universal norms that societies hold about nodding gratitude toward someone who holds a door open, writing thank-you notes after receiving gifts, and dedicating your Saturday to carrying furniture for the people who helped you move. This principle explains why many restaurants adopt the common practice of waiters distributing mints or other small treats when bringing the check. According to research published in the Journal of Applied Social Psychology, when waiters followed up after a meal with a small gift, restaurant patrons tipped up to 23% more in return. Thus, giving a thoughtful gift—whether a handwritten note, small treat, or tidbit of advice—when none is expected is an effective way to increase engagement from the other party.

            The principle of reciprocity has been used to develop the so-called “door-in-the-face” persuasion technique. The premise for this technique is to start with an unrealistic, large request—fully expecting that the metaphorical door will be slammed in your face—and then to follow up with a smaller ask. An example of this would be asking someone if they’d be willing to volunteer for two hours every week for the next year,  and then asking if they’d be willing to volunteer just once. After rejecting a large request, people are more likely to agree to a small favor, presumably to dispel social tension. Starting with a large request and then scaling back the ask signals that you are willing to compromise and give up ground—due to reciprocity, people feel compelled to concede something in return and are more likely to help you out.

Scarcity

            The next principle of persuasion, scarcity, is relatively intuitive and in line with the laws of supply and demand. Psychologically, people crave the very things that they cannot have or things that are less available to them. For example, during the pandemic, the perception that there was a shortage of hand sanitizer or tissues caused people to rush to the grocery store and buy these products. When proposing a deal, it is important to highlight why the opportunity is rare and won’t be around forever. 

Authority

            The tenet of authority describes how, unsurprisingly, people are more likely to take advice from and be persuaded by credible experts and sources. As such, it is important to establish yourself as knowledgeable and trustworthy before attempting to sway the other party. Indeed, a study found that physiotherapists who subtly signaled their authority by displaying diplomas on the wall had more success persuading patients to follow exercise routines. By and large, people are indecisive and exhibit a strong compulsion to turn to others who seem knowledgeable rather than form their own conclusions. As such, subtly finding ways to weave in your credentials—or by cleverly having a colleague introduce and speak highly of you beforehand—is worthwhile. Needless to say, appearing highly confident can set the stage right, affording you greater success with negotiation. 

Consistency

            Consistency establishes that most people like to think of themselves as reasonable and strive to act in a consistent manner with their previous statements and actions. The so-called “foot-in-the-door technique” revolves around the principle of consistency and entails asking people to agree to a small, manageable task. Research shows that people are more likely to agree with a large request after they’ve already agreed to a small one. Several key social psychology experiments have demonstrated the effectiveness of this technique; for instance, Freedman and Fraser (1966) asked residents of a California neighborhood whether they’d be willing to display a giant, unsightly “Safe-driving” sign on their front lawn as part of a public safety campaign. Unsurprisingly, the vast majority of residents declined. However, a group of residents had previously been asked to post a small “safe-driving” placard in their window during an earlier visit. The residents who had agreed to the first task were three times more likely to subsequently agree to display the large, unattractive “Safe-driving” sign in front of their house. An explanation for this is self-perception theory, which states that people observe and use their own behaviours to deduce the attitudes that they must hold. People who comply with a small task and are labelled “supporters” of a cause may conclude that they are philanthropy-oriented people, and continue to agree to larger and larger tasks to stay consistent with this identity.  

            Additionally, the ethically questionable low-ball technique capitalizes on the human desire to stay committed to a course of action. This method occurs when an initial enticing deal is presented, and then the terms of the deal are changed once the person has already committed. After providing an initial agreement, people are unlikely to withdraw their assent, even if a last-minute inconvenient clause is added. It is important to be wary of this technique when purchasing deals that appear too good to be true, especially at car dealerships.

Liking

            This tenet is based on the simple fact that people are more receptive to requests from people that they like. Research has shown that even a conversation in passing can increase liking, as can the mere exposure effect (people tend to like stimuli they encounter often). Physically attractive people are generally deemed more persuasive, and people are more influenced by others who are similar to them. Subtly mirroring the other party’s actions and posture—smiling, arm movements, and so forth—is sometimes taught as a marketing technique. Taking the time to introduce yourself and get to know the other party before delving into negotiations boosts positive outcomes, and genuine compliments or jokes can go a long way. Studies have shown that people are more open to agreement when in a good mood, perhaps due to associating the positive feelings with the request at hand. That said, fear-arousing persuasive techniques detailing risks and consequences have also been proven effective, specifically as urgent calls to action. While both feel-good and fear-inducing messages are compelling, fear-inducing messages only work if a course of action to alleviate the fear is provided—otherwise, the overwhelming emotions may lead to denial. The brain is adept at remembering narrative stories, and framing your request using storytelling or personal anecdotes can help people recall it. 

Consensus

            The last principle, consensus, describes how people tend to go with the flow and follow injunctive norms, or expectations of socially approved behaviour, as well as descriptive norms, or expectations of how most people act. In the face of uncertainty, people often observe how others behave to decide how they, themselves, should act. In persuasion, mentioning that the majority of people do x is an effective way to convince more people to do x. Studies have shown that simple signs in hotels declaring that 75% of people reuse their towels is enough to increase towel reuse rates by 33%. However, whether the persuasion should include injunctive or descriptive norms varies from situation to situation. In one study, signs at Petrified Forest National Park in Arizona declaring that there were “theft losses of petrified wood of 14 tons a year, mostly a small piece at a time,” had the opposite effect than was intended. By normalizing theft as the descriptive norm, every piece of wood stolen seemed less consequential—after all, 14 tons walked away each year. After the park removed the signs, the amount of wood stolen decreased by nearly 80%.

References

Cialdini, R. B. (2003). Crafting normative messages to protect the environment. Current Directions in Psychological Science, 12(4), 105–109. https://doi.org/10.1111/1467-8721.01242

Cialdini, R. B. (2023, June 13). The science of persuasion: Seven principles of persuasion. Influence at Work. https://www.influenceatwork.com/7-principles-of-persuasion/

Myers, D. G. (2012). Exploring social psychology (6th ed.). McGraw-Hill.

Plous, S. (n.d.). Lecture 2.8: The ins and outs of social influence [Lecture]. Social Psychology.

Polanski, T. (2017, January). Dr. Robert Cialdini and 6 principles of persuasion. Jacob McMillen. https://jacobmcmillen.com/wp-content/uploads/2017/01/E_Brand_principles.pdf

Psychology Today. (n.d.). Persuasion. Retrieved July 26, 2025, from https://www.psychologytoday.com/us/basics/persuasion