I think one just knows genuine people. I give the benefit of the doubt until proven otherwise. If someone starts off being helpful and offering friendly advice, but suddenly changes track and gets into heavy criticism and even threats (such as reporting insignificant things like if they suspect plagiarism or whatever), just to be superior, that's just not genuine. They ruin their initial helpfulness by becoming insulting to others perspectives amd being intimidating. Someone like that to me, is not genuine and makes me wonder why they are so angry about what others do (possibility it is something they have done themselves and they project it onto others).