For anyone in a leadership role in an office, being able to identify a toxic employee is critically important. It is like catching a maintenance issue with your car early enough before it becomes serious or addressing back problems before you need surgery.

As I've mentioned before, toxic behavior in an office can spread like the common cold--other employees see the bad behavior and start stewing about it and let the negativity fester. Yet, you don't want to sit around and analyze everyone constantly for signs of trouble. These tips are short and get right to the point. The first step in figuring out what to do about toxic behavior is to identify the toxic person--so here's what to look for:

1. They send short, curt emails

When someone constantly sends short emails or Slack messages, it could be a sign that the person is just busy. No problem. However, from what I've seen in an office, short and curt emails and messages are often a sign that the person is in a bad mood or doesn't really want to put that much effort into communication or collaboration.

2. In-person conversations are always about them

I have a theory that toxic people become toxic because they over-analyze their own state of affairs, and don't have an ability to empathize. It's always about what is best for them. They let that spill over to every conversation, and the preoccupation is not healthy.

3. They always state what they don't like first

Here's a great leading indicator: toxic people start with the negative. They forget to encourage and praise, they don't like to make other people feel good about a project. They like to be right about everything, and they also like you to be wrong about everything.

4. Their negative thoughts keep coming back for more

Another sign of toxicity is that a previous conflict or issue from days or weeks ago keeps coming back. This means the person has a problem letting go and is stewing over things, which causes their thoughts to fester and turn into lingering, lasting negativity.

5. They inspire fear

When toxic behavior starts to infect someone like a virus, it has a way of inspiring fear. You don't like to be around that person but you're not even sure why. The toxicity is like the smell from a bad piece of cheese. Everyone knows it is best to avoid it.

6. You don't know what makes them happy

If you are friends with a toxic person on social media, you probably know a lot about what he or she doesn't like--the things that cause irritation and annoyance. That's a red flag. People who have a brighter outlook make sure you know what they like and what makes them happy.

7. They don't like idle chatter