" Smiling reduces blood pressure by lowering the stress-inducing hormones, such as adrenaline and cortisol. As my mother, who is now in her eighties, navigates the challenges of aging, her mantra has become, “Keep moving and keep smiling.” She has observed the rapid decline of her friends who haven’t. She is striving to stay strong, happy, and vital; her desire to smile is helping her to live a healthier, more satisfying, and longer life. "

― Susan C. Young , The Art of Body Language: 8 Ways to Optimize Non-Verbal Communication for Positive Impact (The Art of First Impressions for Positive Impact, #3)