One of the first things in my book that makes me question someone's intelligence? Stupid spelling mistakes or grammatical errors. Yeah, kinda like how I wrote the headline to this. Yes, it should be "you're", but it's more fun to see this get shared on social media, and for people to immediately comment on the headline without reading the actual article.

Along with that, here some things from Business Insider that can make co-workers think you're dumb. 

  1. Being a know-it-all. Just look up the Dunning-Kruger Effect. Generally the biggest loud-mouth-know-it-all is not the smartest person in the room.
  2. Using emojis in work emails. This one is pretty self explanatory. Use emojis, don't get taken seriously.
  3. Telling inappropriate jokes. On the flip side, if you tell work appropriate jokes, it can make you seem more competent.
  4. Being afraid to ask for advice. It might seem like asking for help will make you seem less competent, but research from Harvard Business School showed otherwise.
  5. You submit work projects with grammatical mistakes. Just take a look at the headline of this article. Do I look competent?
  6. Trying to impress everyone. This one apparently happens most in the first 100 days, when someone is trying to make a good impression. It usually backfires.