Bryan Johnson and his girlfriend Kate sleep in separate beds and homes. Research shows partners cause about six awakenings per night, though couples who co-sleep report better mental health. The tradeoff: women typically sleep worse with a partner, men sleep better, and the choice depends on what works for each couple.
I have never slept with my girlfriend. Yes, you heard that right. Kate and I have separate beds and separate homes. Should you do the same? Here's the data. A study of 55 couples found about 6 partner-triggered awakenings per night. But the science is split. A separate study of 12 couples found that sleeping together came with about 10% more REM sleep and tighter sleep stage syncing between partners. However, the data varies by sex. One study shows that women sleep measurably worse with a partner in bed, while men report sleeping better. Hell yeah, man. That said, in a survey of 1,000 adult couples who slept together report sleeping better overall, less insomnia, less fatigue, and better mental health. The catch is that this was self-reported, so happier and healthier people may just be more likely to share beds. So should you sleep alone or together? It depends. For some couples, sleeping together improves sleep. For others, separate beds might save your sleep or your relationship, possibly both.
