Intelligence, a giant pile of science shows, isn't fixed. There are a whole host of things both large and small you can do to make yourself smarter.

That's the good news. What's the bad?

If your IQ score isn't the be-all-and-end-all of brainpower and your activities and attitude can influence how intelligent you are on a daily basis, then you are just as able to lower your cognitive powers as you are to increase then. Put simply: you can make yourself dumber just like you can make yourself smarter.

And of course you don't want to do that. Thankfully, PsyBlog recently pulled together a handy list of research-backed ways clever people lower their intelligence so you can avoid them. They include:

1. Eating junk food

That bag of chips is bad for your waistline, but did you know it's also bad for your cognitive function? "A high-fat, high-sugar diet causes significant damage to cognitive flexibility, a new study finds," according to PsyBlog. Other science shows your crappy snacks are probably also contributing to your sky-high stress levels. So off to the farmers' market or vegetable aisle with you.

2. Multitasking

Please tell me you've heard this one before. If not, it's time to face reality. Trying to focus on multiple screens at one time makes your brain scream for mercy. "Using laptops, phones and other media devices at the same time could shrink important structures in the brain," says another study cited by the post.

3. Lack of sleep

This one is probably no surprise to you and yet two-thirds of us apparently don't get enough sleep. So here's another reminder of why you should turn in early tonight courtesy of PsyBlog: "The damage that poor sleep does to your thinking skills is mammoth. Sleepy brains have to work harder while short-term and long-term memory is worse."

4. Feeling like an expert

Wait, isn't being an expert a good thing? Of course knowing lots about a subject can be beneficial, but be warned it can also make you complacent -- and therefore dumber. "The more people think they know about a topic, the more likely they are to claim that totally made-up facts are true, psychologists have found," PsyBlog notes.

5. Google

Instant access to all the world's trivia might make you feel more intelligent, but turning to your favorite search engine every time you have a question actually has a big downside. When you're offline, you're clueless (and dangerously, you often don't know it). "When people are truly on their own, they may be wildly inaccurate about how much they know and how dependent they are on the Internet," the lead researcher of a recent study is quoted as saying.

Published on: Oct 8, 2015
The opinions expressed here by Inc.com columnists are their own, not those of Inc.com.