Sleeping together has existed as long as humanity. In the Middle Ages it offered protection against the dangerous night. Financially there was no choice either, separate rooms were a luxury.
Perception today
Today perception plays a role. Not sleeping in the same bed carries the stigma of a relationship growing cold. We rarely admit it.
What research shows
Sleeping together can raise the cuddle hormone oxytocin and lower the stress hormone cortisol. Oxytocin increases optimism and trust. Research from the University of Pittsburgh also shows that sleep quality and relationship quality strongly influence each other.
What counts
There is no universal solution. Each couple decides for itself. What counts: the moment just before falling asleep, whispering, close together. Whether one then sleeps in the same bed matters less than that moment.