You don't have three seconds to make a good first impression. You only have one! A study published recently in the Journal of Neuroscience found that the human brain decides whether a person is trustworthy or not almost instantly. To thwart this unfair biological response and be considered trustworthy in the world of work, appear confident, relaxed, and knowledgeable; use a firm handshake; greet others with a smile; and make eye contact. Listen slightly more than you speak, and always practice the most important piece of advice to instill trustworthiness: Be genuine -- be yourself.