Very often inertia, selfishness, and vanity play the greatest role in our trust in others; inertia when we prefer to trust somebody else, in order not to investigate, be vigilant, or act ourselves; selfishness when the desire to speak about our own affairs tempts us to confide in someone else; vanity when it concers something that we are proud of.
Arthur Schopenhauer, Parerga and Paralipomena
inertia, selfishness, trust, vanity