Actually the mother is the one who invests the LEAST in westen society and probably most others.
Rubbish.
Mothers, by and large, bear the greatest burden of child-rearing in western societies (and elsewhere too, I'll wager). If you want to put a financial value on the mother's work, look up what a child-care worker earns per hour, then calculate how much time the average mother spends looking after her child, then do the maths. The fact that this is unpaid work does not mean that it has no value and does not count as an "investment" in the child.
If you want to talk finantial its still the case that the father provides the most income on adverage and if we look at time and energy its the community which invests the most in a child.
In the traditional patriarchal nuclear family the mother frees up the father to go and earn a wage. She does the child care (unpaid), while he goes off to earn money to support the family. He is not expected to pay the mother for her child care. In return, he is expected to support the child in other ways, and also to suppor the mother.
Of course, in the 21st century, not all family relationships work in this patriarchal way. For example, in many modern relationships, the mother also does some paid work, and the father may actually spend some time with the kids.
to go a step further, even when the parents DO have the child they are quite often more interested in the child doing work and learning from the people it has spent its day with than from themselves, eg "have you done your homework?" "go and do your homework". The knowledge and culture isn't passed down from mum, most of it is passed down from "the village".
Up to when a child starts school, the
primary influence on a child in a western society is usually its immediate relatives, and most often its mother.
It is really not until the child becomes a teenager than the peer group approaches becoming an equal influence on the child compared to its parents and siblings.
"Culture" is a broad term. Culture comes from all kinds of places - family, peers, teachers, the guy at the greengrocer's shop, the internet, TV, books, etc. etc.
I said the COMMUNITY puts more time and effort into raising children than the mother does
Obviously you don't have children. Or, if you do, you really ought to find out how much effort your wife/partner actually puts in - and you should spend some time at home with your children.