Definition
Psychological influence is the broad category of effort directed at changing what another person believes, feels, or does. It spans the whole spectrum from honest persuasion — laying out reasons and letting someone decide — to manipulation, which works around a person's judgment rather than through it.
Seduction, as Robert Greene describes it, is one branch of this category: influence routed through pleasure, attention, and emotion rather than argument. Understanding the larger category makes the branch easier to recognize.
Why it matters
How it works
Influence operates by attaching a desired response to something the target already wants — safety, status, intimacy, certainty. The more the method engages emotion and the less it engages deliberate thought, the harder it is to evaluate from inside. A reasoned pitch invites a counter-argument; an emotional pull rarely announces itself as a pitch at all.
This is why the same techniques recur across advertising, courtship, and politics. They all draw on a small set of human levers, repackaged for the setting.