The cost of the double load lands on the body and the marriage. People carrying it report guilt, a sense of never doing enough, tension with their partner, little interest in sex, and a craving for sleep. Exhausted mothers talked about sleep the way a hungry person talks about food.
When women take paid jobs, the housework and childcare they did before don't go away; they get stacked on top of the job. Added together, paid work, childcare and housework come to about an extra month of labour a year for working mothers compared with their husbands.
Many jobs are built on the unspoken assumption that someone else at home will absorb the surprises, like a sick child or a school closed for snow. The person who gets that support can look fully committed at work. The person who provides it pays for it out of their own time.
A couple can agree to split chores equally and still end up unequal, because the reluctant partner resists quietly instead of refusing openly. He keeps 'forgetting' his turn to cook until the other partner gives up and does it herself. Male dominance at home doesn't vanish; it changes form.
Partners hold different pictures of how a marriage should work. Some want the old split, with a breadwinner husband and a wife centred on home. Others want both partners in the same spheres with equal power, and many sit in between. Men and working-class people tended to prefer the old split, while women and middle-class people tended to prefer equality, so many couples were mismatched from the start.