Can working hard at the office invigorate a marriage? A new study suggests that for working mothers at least, that may be the case.

Working mums tend to be happier with their marriages when they are shouldering heavy workloads on the job, says a four-year study of 169 couples published recently in the Journal of Family Psychology. One reason may be that when working moms' workloads increase, their husbands tend to help out more at home, researchers suggest.