A fun segment from a great piece on sleep research:
Research studies consistently find, he writes, that adults “sleep better when given their own bed.” One such study monitored couples over a span of several nights. Half of these nights they spent in one bed and the other half in separate rooms. When the subjects woke, they tended to say that they’d slept better when they’d been together. In fact, on average they’d spent thirty minutes more a night in the deeper stages of sleep when they were apart. Randall cites the work of Neil Stanley, a sleep researcher at the University of Surrey, in England, who likes to say that there’s only one good reason to share a mattress.
Sounds about right.