Just spitballing, but interaction mutuality can be a proxy for trust, where the more balanced two users' comments, reacts, and zaps are between them, the more you can assume they trust each other. Other relationships are often more one sided, where the trust is one directional. There could also be something like negative trust that is found by a lack of interaction between two people who have many mutual connections. 

 Isn’t that what Twitter does with “show me less” option ? 

 I'm not sure, but it would be cool. 

 was thinking along similar lines.