The lead author of the study, Madeline Sprajcer, explained that, to have the highest quality and most restorative sleep possible, an individual must be in a very certain state of calm. This means that if you have even a lingering trace of anxiety or stress leftover from the day, you’ll still find falling (and staying) asleep to be much more difficult than it should be.⁠ To this end, being in a relationship with someone who consistently makes you feel safe and cared for can be a great way to quiet the cognitive noise that would otherwise keep you awake at night. Sprajcer explains that there are two biological factors at play in this process, in tandem with perceived partner responsiveness: the hormones cortisol and oxytocin.⁠ ⁠ You could consider cortisol your body’s built-in alarm system: When its levels are high, you’ll feel both restless and on guard. It’s the same hormone that spikes when you’re in a stressful situation of any kind, from being stuck in traffic to being caught in a h...