I share myself with others.

Someone in a meeting says they don't understand the slide, and four other people relax at once. That's the mechanism, and it costs whoever goes first about ten seconds of exposure.

Being known is harder than being helpful. Help keeps you on the strong side of the table; disclosure moves you across it. Plenty of very generous people have never once let anybody see them struggling, and are lonely in a way that surprises everyone who knows them.

Handing over something true about yourself — not dramatic, just true — is a form of giving that most people are worse at than they are at giving money or time.