Why is having someone special so important to us human beings? Not just for companionship, for safety, or for convenience, but because we have a need to express ourselves emotionally and intellectually, we all need someone we can trust to talk to, share our experiences, and bounce our ideas off. We want someone with whom we can share life’s pleasures and, most important, someone to give us feedback—to respond to what we say and let us know how we’re doing. We need someone to witness us, validate us, make us feel complete.

When two people communicate openly and regularly, expressing their feelings and emotions, they give each other reassurance and hope and a connection to the future. We find all of this and more when we express ourselves in love. Scientists have proof that the emotional feedback shared between two people in love balances, regulates, and influences their vital body rhythms and keeps them healthy. Heart rate, blood pressure, hormone balance, and blood sugar absorption all are improved when two people become emotionally united in love. In other words, that old expression “They’ve got real chemistry” isn’t merely a metaphor. People in love don’t just come alive, they tend to stay alive and live richer, healthier, more exciting, and longer lives.