4. Affection
Human beings need affection to survive. You might not realize it, but when you have sex, cuddle, or even just lean into each other on the couch while watching movies, your body is releasing oxytocin and that's one hell of a powerful hormone. When oxytocin is released on a regular basis, it boosts the immune system, helps ease depression and stress, aids in heart health, and, ultimately, makes us live longer.