From the moment we're old enough to understand it, we're taught that it's impossible to change other people. The parent always oozing negativity, the boss who can't appreciate any accomplishments, the relentless trash-talking "friend" -- these seemingly unhappy people are who they are, and nothing you can do will change them. Only, that's not entirely true, says one happiness researcher.

Shawn Achor has spent years studying the topic of happiness, even traveling to 50 countries to research positive psychology. The Harvard-trained researcher and best-selling author recently shared the most powerful highlights of his findings in a talk for Oprah's "SuperSoul Sessions" speaker series , explaining how, yes, it is possible to change other people's happiness levels.

"Happiness is an individual choice, but we are influencing people all the time," Achor says.

Of course, if we're not conscious about it, the unhappy people can end up influencing us. But Achor says if you can find a way to "buffer" your brain from that negative influence, you become incredibly powerful.

"If you find a way to ... create a single positive behavioral change, we can watch that positive behavioral change wirelessly ripple out and tip other people's brains towards the belief that our behavior matters, towards the belief that change is possible, and that happiness could actually be a choice," he explains.

Related: How a two-minute exercise can redirect your brain toward happiness

Even just one person hearing Achor's message -- from either a seat at his lectures or from behind a computer screen -- can, by design, spread happiness far beyond themselves.

"As we look at you now, there's no wires connecting you. You're going to scatter across the globe after this," Achor says. "There's no wires connecting us, but our brains have been designed to be wirelessly connected, through a mirror neuron network. We don't process the world; we co-process happiness, we co-process optimism and belief."

This is why one individual's positivity and happiness can change everything, including the other people around them.

"If we can find some way to create a positive effect on other people, we can ripple out not only what our brain is doing, but get other people to do that as well," Achor says.

Watch Shawn Achor's full 32-min. session about the life-altering power of a positive mind

Browse more mini-sessions on SuperSoul.tv

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