We humans are masters of resentment — a characteristic that can be traced back the beginnings of recorded history. Feuds seem to be an indelible aspect of the human condition, but why should this be? We spoke to the experts to find out why we love to hold a grudge, and the importance of letting go.

Do you like to make small talk? Do you prefer one-to-one conversations or group activities? These questions and many others often show up in personality quizzes to reveal how introverted or extroverted you are, but what does that really mean? Here's what science tells us about extroversion and introversion.

The world appears to be in a rough place right now. If you turn on the TV or open up your web browser, you're almost guaranteed to be bombarded by bad news. But is the world really doomed? Or is your animal brain playing tricks on you? Chin up -- things aren't always as bad as they seem.

You go to take a step up onto your porch when you realise it's covered in shimmering, slippery ice. Your mind wants to stop so you don't hurt yourself, but your body isn't going to get the message in time. Here's what's going on in that brain of yours.

Feeling stressed? Tired? Skipping out on work might seem wrong, but according to one neuroscientist, it could end up making you more productive in the long run.

Dr Robert Lustig joined us in the studio to talk about his new book, The Hacking of the American Mind: The Science Behind the Corporate Takeover of Our Bodies and Brains. Dr Lustig is a paediatric endocrinologist who is also author of the book Fat Chance: Beating the Odds Against Sugar, Processed Food, Obesity and Disease. He talks to us about how corporate interests have worked to keep us addicted to pleasure -- and how our addictions have robbed us of happiness.

You're in a long, boring meeting. You look up at the clock again, hoping time is passing by faster than it feels, but instead the clock's seconds hand doesn't seem to move at all. No, the clock didn't just pause to mock you, your brain is playing tricks on you.

If you use Google's Photos app, Microsoft's Cortana, or Skype's translation function, you're using a form of artificial intelligence (AI) on a daily basis. AI was first dreamed up in the 1950s, but has only recently become a practical reality -- all thanks to software systems called neural networks. This is how they work.

Many of us believe that money brings out our calculating sides, inspiring decisions that are motivated by rational self-interest. But evidence suggests that money does the opposite, leading to druglike mental states and irrational choices that are anything but sound.

The short answer? Yes, total sleep deprivation can almost certainly kill you. What's less clear is how it does it.

The human brain is capable of 1016 processes per second, which makes it far more powerful than any computer currently in existence. But that doesn't mean our brains don't have major limitations. The lowly calculator can do maths thousands of times better than we can, and our memories are often less than useless -- plus, we're subject to cognitive biases, those annoying glitches in our thinking that cause us to make questionable decisions and reach erroneous conclusions. Here are a dozen of the most common and pernicious cognitive biases that you need to know about.

What if tomorrow you woke up and decided that you were going to stop speaking? Not for a day, not for a week -- but for, say, 20 years. What effect would if have on your body? What effect would if have on your mind?

Scientists have spotted the parts of the brain that light up when we actively hate someone. There's probably a reason why hate evolved in the first place -- and it's similar to love.

One way to have more time for work and play every day is to sleep a little bit less. But eventually, staying awake for longer periods can have a negative impact on the quality of our lives. So where does the break-even point lie, and can it be shifted?

Dealing with people who exhibit passive-aggressive behaviour is easily one of the most challenging aspects of our social lives. Here's what you need to know about this annoying personality quirk and how you can handle people who express their hostility in indirect and backhanded ways.

There may be as many as 80,000 American prisoners currently locked-up in a SHU, or segregated housing unit. In 2014, NSW, NT and WA corrective services could not give a figure for how many people are in solitary confinement as it is constantly fluctuating. Solitary confinement can cause irreversible psychological effects in as little as 15 days. Here's what social isolation does to your brain, and why it should be considered torture.

Being a teenager is as infuriating as it is amazing. Caught between childhood and adulthood, adolescents often have fully developed bodies, but their brains are still under construction. Here's what neuroscience is learning about the remarkable teenage brain, and how it affects behaviour.

You can have all the good intentions in the world, but they're only as good as your self-control. Here's what you need to know about the neuroscience of willpower -- and what you can do to make your will even stronger.

Why do we smile and even giggle when we're afraid? Are we trying to work things out? Or are we trying to convince everyone, even our attacker, that nothing's wrong? Here's what science has to say about "fear grinning."