It seems strange when you think about it, but the single most important element in any business interaction is the one that people usually give the least thought to beforehand.

I’m talking about trust—one five-letter word that describes the single most important factor in determining whether an interaction will succeed or fail.

In a culture that continually celebrates individualism, it’s easy to forget sometimes that by nature all business is cooperative and interactive. Even the most resourceful sole entrepreneur depends upon others – his clients, at a minimum – in order to accomplish anything. Human interaction is the foundation of all business activity, and successful interaction begins from a basis of trust.

Trust is the ability to have confidence or faith in a person, team or process. Whether you’re making a sale, collaborating on a project, getting hired into a new position or simply trying to maintain orderly daily operations of your office, you’re not likely to get far if you don’t trust those you’re working with – or if they don’t trust you.

Establishing a foundation of trust is the critical first step towards the success of any business or interpersonal interaction. Rather than working consciously towards establishing a basis of trust, though, we usually rely on relatively random factors to create this basis for us, and hope for the best. We rely upon gut feelings, chemistry, or the expectation of shared interests to get us over any initial trust hurdles, counting on good fortune to sustain the momentum.

Too often, we find that this is simply not enough. If you think about any occasion where you’ve felt that a client or colleague “let you down,” chances are that what you’re actually reacting to is a breakdown in reciprocal trust. While obviously it’s not possible to sustain trust relationships with everyone – some people simply aren’t trustworthy – it is possible to consciously work to build a stronger, more resilient foundation of trust at the outset of a relationship (or work to rebuild one if it has become frayed over time).

There are a number of steps you can take to nurture trust, but for the purpose of this article we will focus on one of the simplest and most fundamental of these: Start by trusting yourself.

What does that mean? It means to trust yourself enough to be yourself. Be authentic. Trust in your own skills, qualities, knowledge, personal appeal, and unique characteristics to place your genuine nature on display, and frame your interactions with others on that basis. Worry less about what the other guy expects to see or hear from you; worry more about making sure that what you present of yourself to the wider world is a genuine representation of your authentic self. “To thine own self be true,” as Shakespeare said.

Here’s why: Authenticity is nearly impossible to fake – and it is usually nearly impossible to resist. If you think about when you’ve encountered it in others, chances are you’ll find that these were some of the people you’ve been most strongly drawn to, found to be the most memorable – and in all likelihood, trusted implicitly.

And here’s the second reason: Most human beings tend to mirror one another’s behaviors, moods, and attitudes. When you begin an interaction radiating authenticity, you give the people around you the permission and encouragement to do the same. That lowers barriers, increases the comfort of the interaction, and encourages clear, open communication – which builds a great basis for mutual trust.

Will this magically make everyone like you or want to do business with you? No, and that’s a good thing. A successful long-term business relationship depends on mutual trust. Those who are either disinterested in or resistant to helping establish that mutuality probably aren’t good candidates for a solid cooperative relationship. Weeding them out early on saves time, energy, and the disappointment associated with being “let down” later.

So go ahead: Actively invest in establishing trust, rather than counting on luck. You’ll find it pays solid dividends later.