" The four biggest reasons you’ll fight Why will you fight? I mentioned four consistent sources of marital conflict in the transition to parenthood. Left to their own devices, all can profoundly influence the course of your marriage, and that makes them capable of affecting your child’s developing brain. I’ll call them the Four Grapes of Wrath. They are:        •    sleep loss        •    social isolation        •    unequal workload        •    depression "

― John Medina , Brain Rules for Baby: How to Raise a Smart and Happy Child from Zero to Five