Discuss the link between polygamy and the dawn of agriculture

It has been said that human evolution which cultured the human behavior involving sexual relationship might have been influenced by agriculture. 10,000 years ago humans have become independent and learned how to produce and create plantation which had altered human condition back then. 

Older children in a large family is really helpful because older kids know more, for example, doing the laundry or ironing clothes. These are more suitable for older children at home because they are more responsible and if a little kid irons the families clothes the little kids might get burned because they don't know how to do it. Older children are also helpful because if their mom is doing work and their mom needs someone to take care of the other littler kids, the older kids can help and watch them.