edit- In European history
I don't feel like I ever understood how dowry worked. This is probably due just to lack of knowledge about social dynamics of the times. What seems likely to me, in a civ that doesn't treat women the way we try to now, is that a man who is seeking a wife would be paying her father, not the other way around.
To me a suitor paying a father to take one of (the father's) daughters makes it seem like having a daughter was a burden the father wished to be relieved of, rather than that she was an asset he...eh, produced?...that would be valuable to be traded (for something like a dowry) to someone who needs it (a guy who needs a baby factory or whatever).
I was hoping to learn a bit more so I understand why my thoughts are completely wrong from what actually happened. Thanks
While the daughter is, in some ways, a burden for her father in pre-modern European society, making the dowry somewhat sensible according to the idea that the dowry is for the groom, the dowry actually isn't intended for the groom specifically. A groom certainly appreciated the dowry as an increase to his family's income, but there's more to the practice.
The dowry is intended to ensure that the wife will have a piece of property that she will inherit (or at least control) in case of the husband's death, maiming, or destitution. The dowry was often in the form of land, for those who owned land to give, but could also come in the form of coins or other non-perishable goods (like large chests for holding linens).
In many jurisdictions, dowries were completely inalienable pieces of property. If the husband intended to sell the property (or spend the money) without suitable replacement of value, the wife could bring the case to court to prevent him from doing so. In some places, the wife even determined how the dowry would be split among her children, even if she died before her husband.
Also, for women of a poor background, many regions required them to provide their own dowry in order to be legally married (which, naturally, resulted in cohabitation for the poorest). The dowry is proof that the wife brings "something" to the table besides her person, and helps ensure that the newlyweds will have some degree of economic security in their lives.
It's also worth considering that, in European history, the custom of dowry wasn't always paid solely by the father. For instance, in Germanic culture (and in various places throughout the medieval period), new husbands practiced the custom of morgengabe (literally, "morning gift"); the wife could freely use this gift as her own personal property.
Source:
Raffaela Sarti, Europe at Home
Steven Ozment, The Burgermeister's Daughter
You are confused about dowry and bride price. Dowry is money paid to the prospective husband by the bride's family. Bride price is money paid by the prospective husband/husband's family to the family of the bride or the bride herself. Some societies have one, some have the other, and some have both or neither.
Using this information, you will probably get a much more comprehensive and informative answer about what societal pressures and things lead to which at /r/askanthropology.