Just how terribly destructive can spending time with toxic people be? Science offers a few clues (and they're all disturbing).

First, psychological research shows that criticism and insults are five times more powerful than compliments. That means if you want to keep your marriage flourishing, for instance, you need to have five positive interactions to make up for every negative one.

And what's true in relationships is true at work too. Jerks, sadly, have more impact than superstars. When Harvard Business School professors calculated the cost of hiring a toxic employee versus the value of hiring a superstar, they found that adding a jerk to your team will actually cost you twice as much as hiring one A-player will earn you.

Taken together, the evidence shows that even minimal interaction with negative people can have an outsized impact on your performance and happiness. So what should you do about it? If a helpful thread on question-and-answer site Quora is anything to go by, the answer is simple: just avoid these types of energy-sucking, toxic people like the plague.

1. Gossip mongers

"Watch out for those types who deliberately tear other people down. One day, they will tear you down too," cautions writer Nurjean Chaneco. Likewise, engineer Lamia Amine warns readers to steer well clear of "people who want to know every single thing about your life and others' lives, just to gossip about it."

2. The hopelessly self-destructive

If someone refuses to take responsibility for their terrible choices, their drama will infect your life and sap your energy, warns attorney Athena Ponce.

"I'm not saying you should shun anyone with bad habits," she writes. "But there are some people who become defensive, combative, and full of excuses when you point out obvious, severe lapses in judgment in attempts to help them.... If having to provide support for people who act this way causes you stress and never-ending frustration, it's best to stay away. They have no intention of growing as people."

3. Conversation hogs

Aspiring software developer Liam Hayes calls this type of person "a conversational narcissist." Ponce describes them this way: "people who talk a lot about themselves but who don't show an equal, genuine interest in hearing from you about yourself."

They could include a friend who's always looking for advice but never asks you about your own life, the showboat who gets a thrill out of endlessly relating his latest adventures, or the well-meaning acquaintance who can't seem to maintain a conversation about anything other than her therapist. But whichever sub-type you come across, avoid them and don't feel guilty about it. As Ponce points out, "these people would be satisfied to perform in front of anybody."

4. Emotional vampires

What's an emotional vampire? "They can take different forms--some try to elicit endless pity for problems they don't seek to solve, some like to make you miserable by criticizing you mercilessly, some talk sh*t about everybody else and try to make you complicit in their negative worldview, some try to control you and make you feel like you need to account for your actions to them, etc. The one unifying element is that after every interaction you feel emotionally drained, fatigued, and listless," explains author Martyn V. Halm. Don't play their games.

5. Walking selfies

Writer Todd Brison refers to this type as "shiny people"--they always look polished on the outside, but their real personality doesn't match their exterior. "Honesty is a shiny person's biggest fear. They don't want you to know them. They want you to know the filtered, curated, guarded version you see every day," he writes. Who has time for that?

Psychology enthusiast Marcus Geduld likewise cautions against wasting your time on "people who are rarely vulnerable." These "folks who put up walls--or who play personas" are often simply wounded and self-protective, he acknowledges, "but it doesn't work for vulnerability to be one sided."

6. The ultracrepidarian

Max Lukominskyi, chief marketing officer at Slice Planner, has a fancy word for this personality flaw--ultracrepidarianism--but ladies, you probably just know the problem as mansplaining.

Whatever your gender, you definitely should avoid these people who feel entitled to dispense wisdom and advice on any subject, no matter whether they have the faintest idea what they're talking about. "Such know-it-all guys never give an advice worth listening to," concludes Lukominskyi. Amen to that.

7. Green-eyed monsters

If someone needs to minimize your strengths and achievements to make themselves feel better, you don't need them in your life, a number of respondents caution. Stay away from people who don't know "how to appreciate your hard work and can't rejoice in your accomplishments," suggests operations coordinator Anshul Sharma, for instance.

Ponce also warns readers away from "people who become envious at your success, good fortune, or positive attributes.... True friends are genuinely happy for your good fortune. They don't try to diminish it with negative reactions or make you feel guilty for sharing your happiness."

8. The "calm down" crew

Yes, some problems are bigger than others, and it is possible to be overdramatic about minor issues, but you're not going to get much benefit out of a relationship if the other party constantly tells you you're just being oversensitive. That's why Geduld always avoid those who tell others to "calm down."

"This is almost always condescending. I've never seen it help," he claims. "In my experience, people who say 'calm down' tend to believe they're rational adults and that whoever they're talking to is behaving like a child."

He's also not a fan of the phrase "first world problems" for similar reasons. "Whatever problem anyone is having--no matter how much he's privileged compared to other people--it's a real problem for him. It's something that is making him unhappy," Geduld writes. "I have a general disdain for anyone who denies or belittles anyone else's feelings."

Are there any other types of people who should be added to this list?