People can be hard. It can be difficult to work out what who to trust and who to distrust. Some people need special care in handling, some people are just toxic. Here is a series of ideas that helps you to get from meeting with the assumption that they are decent, to a potential recognition that this person may need to be treated with lots of caution.
Principle of Charity: “Interpreting a speaker’s statements/actions in the most rational way possible and, in the case of any argument, considering its best, strongest possible interpretation.”[More]
When you meet a person, or are not aware of all of the facts, assume they are trying to do the right thing with the information and abilities they have, that they are trying to say the right thing and don’t know how to say things better, and any ill consequence is hopefully ignorance.
Hanlon’s Razor: “Never attribute to malice that which is adequately explained by stupidity.” attributed to Robert J. Hanlon[More]
Mallice is actually quite rare. When you are confronted by an anomolous (rare) situation that seems mallicious, in the absense of concrete evidence that this likely to be a stupid error.
Margaret Atwood ‘…the difference between stupid and ignorant was that ignorant could learn.”Alias Grace Quotes by Margaret Atwood
If you’ve talked to the person about what went wrong and why that was a problem, then ignorant people will learn and not repeat the rationally explained and reasonably evidenced error. You shouldn’t have to explain too much or go into too much detail to be able to tell the difference between someone trying to learn what went wrong and someone refusing to engage (mallice), or incapable of engaging (limited capacity aka stupid) in the process.
Grey’s Law: “Any sufficiently advanced incompetence is indistinguishable from malice”, unknown author[Gooden, Philip (2015). Skyscrapers, Hemlines and the Eddie Murphy Rule: Life’s Hidden Laws, Rules and Theories. Bloomsbury Publishing. p. 83. ISBN 978-1-47291503-0.]
While this is a useful idea, the original author is not known. It borrows both Clarke's Three Laws regarding sufficiently advanced science being indistinguishable from magic, and Hanlon's Razor from above.
At some point, it doesn’t matter if the person is mallicious or stupid, if they keep hurting you, they are toxic to you. Get away from them.
This sounds easy, but can be very hard – especially if the person is a parent or child and there is a dependent relationship between the two.
If you need some help to navigate if a situation is toxic or not, speak to a trusted friend, or see a therapist to help get a reality check. Therapists are also generally good at helping you find a way out of messy situations with toxic people, even families.