How we make decisions, and how to reach people who’ve already made up their minds

You’re scrolling Netflix at 10 pm, exhausted. You don’t read a single review or check Rotten Tomatoes. You pick the thumbnail that catches your eye: a face, a pose or gesture, a moment that sets the expected tone of the movie. Now contrast that with the last time you bought a car, or researched a medical diagnosis, or tried to understand a ballot measure you actually cared about. Different mental gears entirely. That difference has a name: the Elaboration Likelihood Model.

Developed by Richard Petty and John Cacioppo in the 1980s, the ELM explains how people process persuasive information differently depending on their motivation and ability to think critically. “Elaboration” refers to the mental effort invested when considering a message. The model describes two routes that effort can take.

The central route involves careful evaluation based on logic, evidence, and argument. The peripheral route relies on superficial cues — the attractiveness of the person talking, the length of the message, the right endorsements. Central route processing tends to produce more durable, resistant attitude change. Peripheral route processing tends to produce quicker, more temporary shifts. We all use both of these decision routes all the time.

The key factors are motivation and ability. When a topic feels personally relevant and you have the time and knowledge to engage with it, you’re more likely to take the central route. When you’re pressed for time, emotionally overwhelmed, or the topic just doesn’t feel urgent, the peripheral route takes over. 

Choosing a mobile phone

• Central route: Researching specifications, reading reviews, comparing features against your actual needs.
• Peripheral route: Everyone in your circle uses this brand.

Choosing a movie on Netflix

• Central route: Reading reviews, watching trailers, considering the director or genre, with extra calculations if you’re watching with kids or a partner.
• Peripheral route: That thumbnail is a winner.

Choosing a political candidate

• Central route: Investigating policy positions, watching long-form discussions, reading their work, researching their financial backers and lobbyist connections.
• Peripheral route: This one has the correct party letter beside their name.

Choosing a street design

• Central route: Analyzing surrounding land use, comparing traffic safety outcomes, studying how similar designs performed elsewhere.
• Peripheral route: This one has bike lanes.

Two earlier figures cast a long shadow over how we think about persuasion.

Walter Lippmann, the father of modern journalism wrote in the early 20th century that people are limited in their ability to engage with complex public issues. The sheer scale and complexity of modern society means most people rely on mental shortcuts (stereotypes, prior assumptions, secondhand impressions) to form opinions. Lippmann set the stage for…

Edward Bernays, Freud’s nephew and the father of modern public relations, who took a harder-edged view. He argued that people are driven primarily by unconscious desires and emotions rather than reason, and that experts needed to manage public opinion. He openly acknowledged that public relations could be used for good or ill, depending on the values of whoever was wielding it. He mostly assumed those people would be his clients.

Where Lippmann and Bernays tended to treat people as fixed in their cognitive tendencies, the ELM recognizes that the same person can engage deeply or superficially depending on context. Where Bernays saw persuasion as a one-way transmission from expert to audience, the ELM frames it as a dynamic interaction shaped by source, message, and audience together.

What this means for urbanism

The goal of community engagement isn’t always the same. Sometimes you’re trying to educate an audience. Sometimes you’re asking them to choose between two design options. Sometimes you’re trying to build lasting support for a long-term policy shift. 

The ELM central route will produce more lasting and consistent attitude change, but it requires an audience that’s motivated and equipped to engage. That means translating complex subject matter into digestible talking points, connecting new information to things people already care about, and being able to meet people at varying levels of knowledge. You’re the dot-connector. The burden of accessibility is on you, not them.

The peripheral route gets faster results, but they’re more fragile. Credibility signals, visual design, trusted messengers, and social proof all matter, especially with audiences who don’t have the background or bandwidth to evaluate technical arguments on their merits. 

Both routes require storytelling. For the central route, storytelling makes information memorable, like vivid mental images, emotional resonance, and concrete examples that anchor abstract arguments. For the peripheral route, storytelling builds presence and credibility with people who are making fast judgments about whether to trust you at all.

Our instinct is to judge anyone who relies on mental shortcuts. But it’s human nature and we all do it. The ELM isn’t a critique of how people think, it’s a candid description of it. Once you accept that, you can start communicating with people instead of talking past people.