Mother, Mother, Mother then Father
UK government ran some economic experiments in 1970s for child tax credit. By then, UK like many other countries a typical family was: mother stays home and raises kids, and father goes out works the whole day and brings money. At the beginning they would send money to moms to spend on their children. Later, the government thought to change the scheme and instead of sending money, they reduced the amount of tax, which ended up as a raise of payroll for the father. So, in the second scenario the money went to the pocket of father instead of mother.
Interestingly, it was found out as a result of this experiments that when father got the extra money they used it more on tobacco and alcohol and only a little channeled to their kids, whereas moms genuinely used the money for the well-being of their kids.
No wonder then Allah -who is the creator and knows the inner psyche of all of us — gave preference to mothers over fathers in respect, treatment and dutifulness especially in their old ages.
Leave you with Chapter 31 (Luqman) verse 14 from Quran
And We have enjoined upon man [care] for his parents. His mother carried him, [increasing her] in weakness upon weakness, and his weaning is in two years. Be grateful to Me and to your parents; to Me is the [final] destination.