Should couples use a joint bank account?

I made a joke on Twitter:

But now that joke is backed up with data:

“Across five studies including evidence from a largescale longitudinal survey, we find that couples who pool all of their money through the use of joint bank accounts experience greater relationship satisfaction, compared to couples who keep all (or some) of their money separate. “

Association for Consumer Research

I wonder what came first? The happy marriage or the joint bank account?

My wife and I share all debt and income, but keep a small amount for ourselves as “personal cash”.

How do you manage your couple finances?