There are a few things that stand out as red flags when meeting or getting to know new people.

1: Inconsistent stories

I once knew a guy who had a story for everything. It would be one thing if his life experiences matched his stories. It is another when the stories are outright falsehoods.

If there is a willingness to lie about experiences, that person will likely lie about other things as well.

2: Being overly familiar

It is enjoyable engaging with someone pleasant and interested in a conversation. Another entirely if a new unknown person begins acting like you best friend an hour after first contact. Learning and respecting each others' boundaries is important.

3: A mean sense of humor

Humor is helpful for keeping life in perspective and making heavy situations light. It says a lot about someone if their humor relies on low blows, one-upmanship, and cruel jokes. It is important to contextualize our humor (it is as unique as each individual), but there is no place for harmful humor.

4: Discounting and minimizing

Minimizing accomplishments, discounting feelings, and generally being oppressive rather than open with others is a flag. Doing this to yourself because of low self esteem is a problem, but it is another entirely to gaslight others.

5: Not asking questions or contributing to the conversation

Asking questions and adding commentary is how relationships are formed, and sustained. Without either, there is no interest. And little reason to continue conversing.