It’s the foundation behind the happiest marriages and the intangible quality that makes the best teams click. Put simply, it’s the key ingredient to all successful relationships.

It’s called trust.

 But how do you really gain another person’s trust?

Paul J. Zak, professor of economics, psychology, and management at Claremont Graduate University, set out to answer that question. 10 years ago, he began measuring the brain activity of working people “in an effort to understand how company culture affects performance.”

He shares the details of these experiments in a recent article for the Harvard Business Review entitled, The Neuroscience of Trust.

Zak theorized there must be a neurologic signal that indicates when we should trust someone. Knowing that a rodent’s brain exhibits a chemical called oxytocin when it deems that another animal is safe to approach, he wondered if something similar happened with people.

By means of numerous experiments, Zak and his team discovered that it did: The amount of oxytocin a person’s brain produced predicted how trustworthy they would be. Further, when subjects received synthetic oxytocin (through nasal spray), they increased greater levels of trust. For example, one experiment called for participants to send money to a stranger, knowing whatever amount they sent would triple and that the recipient could then choose whether or not to share the reward with the giver. Giving people 24 IU of synthetic oxytocin more than doubled the amount of money they sent.

Zak and his team then spent the following years studying the promoters and inhibitors of oxytocin. In doing so, they identified eight factors leading to increased levels of trust:

1. Recognize excellence.

According to the data, “recognition has the largest effect on trust when it occurs immediately after a goal has been met, when it comes from peers, and when it’s tangible, unexpected, personal, and public.” Public recognition also provides opportunity for high-performers to share best practices.

2. Provide a challenge.

“When a manager assigns a team a difficult but achievable job, the moderate stress of the task releases neurochemicals, including oxytocin and adrenocorticotropin, that intensify people’s focus and strengthen social connections,” writes Zak. “When team members need to work together to reach a goal, brain activity coordinates their behaviors efficiently.”

A word of caution, though: This only works “if challenges are attainable and have a concrete end point; vague or impossible goals cause people to give up before they even start.”

3. Give people freedom.

Trust begets trust: A 2014 Citigroup and LinkedIn survey indicated almost half of employees would forego up to a 20% raise for greater control over how they work.

4. Provide ample choice.

When employees can choose their projects, they take on greater ownership and are more focused in their work.

5. Be transparent.

Every company says they want it, but few are doing it right: Only 40% of employees say they’re well informed of their company’s goals, strategy, and tactics.

“This uncertainty about the company’s direction leads to chronic stress, which inhibits the release of oxytocin and undermines teamwork,” writes Zak. “Openness is the antidote.”

There’s nothing worse than the feeling that leaders don’t care about keeping you in the loop, or even worse, that they’re keeping secrets. Make sure your vision, intentions, and methods are clear to everyone on your team–and that they have access to the information they need to do their best work.

6. Go beyond work.

The data indicates that the most revered managers show interest in what happens in their teams’ lives, outside of work. This contributes to feeling the manager or team lead is invested in him or her as a real person.

Additionally, work lunches and team-building activities help deepen connections and foster trust.

7. Provide opportunities to grow.

“High-trust companies adopt a growth mindset when developing talent,” writes Zak.

The best business leaders work together with employees to help them reach their personal and professional goals. Frequent and consistent communication, along with proper follow-through, can help make sure that happens.

8. Show vulnerability.

Simply by asking others for help, leaders help stimulate oxytocin production in others, according to Zak’s research. In turn, this increases trust and cooperation.

By following these eight steps, you put your people’s best interests front-and-center. Do it consistently, and the trust will surely follow.