Psychological ownership
The feeling that something is 'mine' — even without legal title — and the investment and care that feeling brings.
What it means
Psychological ownership is the state in which people feel that a target — an object, idea, role, organization, or piece of work — is theirs, regardless of formal ownership. It arises through three routes: controlling the target, coming to intimately know it, and investing oneself in it through effort and creation. Felt ownership satisfies needs for efficacy, self-identity, and having a place, and it motivates stewardship, citizenship behavior, and resistance to change that threatens the possession. The nuance is a dark side: strong ownership can breed territoriality, refusal to share, and inflated valuation of one's own contributions. It matters in organizations and product design because granting genuine control, knowledge, and personal investment converts users and employees into committed caretakers.
Examples
An employee who built a process from scratch defends and improves it long after it stops being formally her responsibility — and bristles when others change it.
A tenant who repaints the flat and rebuilds the garden starts calling it 'my place,' mending the fence the landlord has ignored for years — with no deed to her name.
Wikipedia editors who have written and watched over an article for years revert a stranger's tidy-up within minutes, though nobody owns the page.
First described in Pierce, Kostova & Dirks (2001, 2003).