According to a new U.S. study, delayed marriage and childbearing lead to increased stress for men and women. Delaying marriage and having kids means that the biggest family demands often fall at the same time that career demands are great, especially among the well-educated, while it increases the chance one’s parents might start to have poor health and need help, before the children are fully grown. American moms are participating in the labour force at a greater rate, the study found, doing 22.6 hours of paid work on average in 2008, up from 18.8 in 1985. At the same time, mothers increased the time they spend on childcare to 13.9 hours a week from 8.4 in 1985, but housework time went to 17.4 hours from 20.4. They spent less time on self-care, too. Fathers have increased working hours from 35.7 in 1985 to 39.5 in 2008, and have upped the time they spend on childcare from 2.6 hours per week in 1985 to 7.8 hours today.