The secret to lasting happiness might be neatly summed up in a cheesy neuroscience joke: "The neurons that fire together, wire together."

"It’s a classic saying, and it’s widely accepted because it’s very true," neuropsychologist Rick Hanson, author of Hardwiring Happiness: The New Brain Science Of Contentment, Calm and Confidence, tells The Huffington Post. “The longer the neurons [brain cells] fire, the more of them that fire, and the more intensely they fire, the more they’re going to wire that inner strength –- that happiness, gratitude, feeling confident, feeling successful, feeling loved and lovable.”

But on a day to day basis, most of us don’t stay with our positive experiences long enough for them to be encoded into neural structure (meaning there's not enough wiring and firing going on). On the other hand, we naturally tend to fixate on negative experiences. Positive and negative emotions use different memory systems in the brain, according to Hanson, and positive emotions don’t transfer as easily to long-term memory.

Hanson argues that the problem is we're wired to scout for the bad stuff -- as he puts it, the brain is like velcro for negative experience and teflon for positive ones. This "negativity bias" causes the brain to react very intensely to bad news, compared to how it responds to good news -- research has even shown that strong, long-lasting relationships require a five to one ratio of positive to negative interactions in order to thrive, by virtue of the fact that the negative interactions affect us so much more strongly. The brain has evolved to be constantly scanning for threats, and when it finds one, to isolate it and lose sight of the big picture, according to Hanson.

"We've got this negativity bias that's a kind of bug in the stone-age brain in the 21st century," he says. "It makes it hard for us to learn from our positive experiences, even though learning from your positive experiences is the primary way to grow inner strength."

The way to "hardwire happiness" into the brain, then, is to take in the good -- being present to life's tiny, joyful moments.

“[Lingering on the positive] improves the encoding of passing mental states into lasting neural traits," says Hanson. "That’s the key here: we’re trying to get the good stuff into us. And that means turning our passing positive experiences into lasting emotional memories."

Hanson shared some of neuropsychology's best secrets for overcoming your negativity bias and hardwiring happiness into the brain, optimizing your potential for joy.

Take in the good.

We all encounter positive moments each day, and no matter how small or seemingly insignificant they are, they can be instrumental in changing our perspective. But in order to do so, we must take the time to appreciate these moments of joy and increase their intensity and duration by lingering on them for longer, effectively "wiring" them into our brains.

"People don't recognize the hidden power of everyday experiences," says Hanson. "We're surrounded by opportunities -- 10 seconds here or 20 seconds there -- to just register useful experiences and learn from them. People don't do that when they could."

When you appreciate and maximize the small, positive experiences, he says, “increasingly there’s a sense of being filled up already inside, or already feeling safe inside, or already feeling loved and liked and respected. So we have less of a sense of striving ... Insecurity falls away because you’ve got the good stuff inside of yourself.”

Focus on the positive experiences with the greatest personal impact.

Certain experiences will have a greater positive effect depending on your individual negativity bias at the time. For instance, if you're worried about a health scare, you need experiences that address this worry -- so rather than seeking success or praise at work, you'd want to look for things that gave you a sense of safety or a feeling of wellness.

"You want experiences that are matched to your problem, like matching the medicine to the illness," Hanson says.

We have three fundamental needs for safety, satisfaction and connection, he explains. So if you have a safety-related issue like a health scare, you'd want to seek positive experiences that boost your feelings in that sector. If the issue is connection-related, you should focus on small moments of positive interaction with others. And if you're anxious and feeling threatened, it would help to feel stronger and more protected inside.

Be on your own side.

An essential ingredient of happiness, as research has recently reaffirmed, is setting an intention for joy and then insisting upon it.

"We don't get on our own side; we don't take a stand in which we are for ourselves, and that's foundational," says Hanson. "There's a joke in the therapy world: 'How many therapists does it take to change a lightbulb? Only one, but the lightbulb has to want to change.' It's lame, and it's profound, because right there is square one."

He explains that if someone we love is upset or worried, we try to help them move beyond that state of mind. But when we are upset or worried ourselves, we often don't help ourselves the same way. Instead, we tend to stay upset and ruminate over things longer than we need to.

Maintain a sense of wonder.

Einstein once said, "He who knows it not and can no longer wonder, no longer feel amazement, is as good as dead, a snuffed-out candle." And when it comes to taking in the good, a sense of wonder is key. Experiencing moments as fresh and new, with a childlike awe, allows them to stick in the brain for longer, potentially becoming part of our lasting emotional memory.

“The more that things seem fresh and new, the more that you’re looking at them with beginner’s mind or child’s mind, that’s going to increase brain structure because the brain is always looking for what’s new,” Hanson says.

Open your eyes and look around.

The secret to bliss could be as simple (and extraordinarily difficult) as paying attention. Mindfulness -- the cultivation of a focused awareness on the present moment, developed through practices like meditation and deep breathing -- is perhaps our greatest tool when it comes to increasing our capacity for happiness.

“I think of attention as the combination of spotlight and vacuum cleaner: it illuminates what it rests upon, and then shuuup! It sucks it into our brain.," Hanson says. "The problem is, most people don’t have very good control over that spotlight, and they have a hard time pulling it away from what’s not helpful.”

It can be very difficult to pull our attention away from the negative, which can take the form of rumination, self-criticism, obsession and anxiety, according to Hanson. But one way to change this, and to create more lasting positive memories in the brain, is to make a concerted effort to notice those little, everyday pleasant encounters: A smile from a stranger, a small gesture of caring from a friend or a little personal victory.