
According to Kobayashi’s studies, 26 percent of married couples sleep in separate beds. Kobayashi also claims that four out of ten married couples over 60 don’t share a bed, and that 53 percent of spouses whose children have moved out prefer to sleep solo. There you have it. I personally think it's due to their lifestyle when both of them are working (which is pretty common nowadays) and they have different working schedules /work overtime, in order to not disturb the other or wake them up they could prefer to sleep separately. Also it's pretty common for the mothers to sleep in separate beds to be next to the newborn/baby. And in old age when the passion has "died down" they might feel more comfortable to sleep alone? Idk
Japanese couples don't sleep together?