Knowledge-transfer trust, or "epistemic trust," is a social skill learned in childhood. Developing this trust is a process in which parents teach their children to assess with whom they can lower their natural guard regarding knowledge transfer, and with whom they should not.
An important part of the assessment is to observe how someone actually feels about you and what interests are at stake. The assessment is valuable because a large part of the knowledge is that it is impossible or even impossible to yourself to investigate to what extent the transferred knowledge can be trusted.
The intertwining of being able to trust someone and utilizing their knowledge also reveals something else. It's important for children to be receptive and teachable, and then receive appreciation for it. This creates the image that they are worth sharing knowledge with.