It could be because they are weaker, more sensitive...? What can be the reasons? Thanks :)
Bianca: You can date this from an early point in history to some extent it still goes on today. In earlier times man was not to blame for his low opinion of the woman and the woman had low self-esteem themselves . They succeeded in primitive times not to get social recognition, because they did not function in an emergency : it was not a spectacular heroine in times of crisis . Motherhood was a distinct disadvantage in the struggle for existence : their mother's love wouldn’t led them participate in wars, so the women were prevented from defending the tribe. Primitive women also made themselves unintentionally depending on their admiration for the man and cheering his fighting spirit and virility . By this glorification of the warrior male ego which elevated him, while the ego of the wife was reduced by the same extent and there were more dependent ; a military uniform is still a strong incentive for the feminine emotions.
In the more advanced races , the women are not as big or strong as the men . Because the woman was weaker , she was tactful ; she learned to use her sexual charm instead. She became more vigilant and more conservative than men , although somewhat less profound. The man was on the battlefield and in the hunt, which subsequently led to the majority of the woman, also subsequent to the woman’s manner leading their households strategically , which even made the most witted men usually outwitted.
I don't think that the proposition is universally true. There are examples of matriarchal societies in the American Indian cultures and also some extant African cultures. Those typically have not (or were not) influenced by static farming practices. The current African matriarchal societies have been impacted by religious beliefs imported from middle Eastern religions (like Islam and Christianity).
So I believe religious beliefs are one influence which devalues the role of women.
Another has been the influence of sedentary agricultural practices and you can see that in societies like those of the Indian sub-continent and also China, where sons are valued above daughters. I believe that is to do with the value placed on food production.
Another has been the role of warfare where males (mostly) do the fighting. The idea of a perfect warrior was not such a good idea for Spartan males of course, but the women fared better there.
So a complex answer like all things.