A message changes someone’s attitude or behavior. Persuasion is that process of influence through communication. It can be deliberate, as in advertising or political campaigns, or incidental.

Dual-process models distinguish central-route processing, which carefully evaluates arguments, from peripheral-route processing, which relies on cues such as source attractiveness or emotional appeal. Source credibility, message quality, audience involvement, and channel all affect outcomes. Resistance to persuasion can be strengthened by forewarning and inoculation with weakened counterarguments.

Persuasion research informs public-health campaigns, negotiation, and the design of effective warnings. Ethical questions arise when techniques exploit cognitive biases or emotional vulnerabilities. Understanding persuasion helps both those who wish to influence responsibly and those who wish to remain free to choose.

• Attitude or behavior change through communication
• Operates via central and peripheral routes
• Influenced by source, message, and audience factors
• Can be resisted through inoculation and awareness