What social and political norms did Enlightenment thinkers challenge? What were the effects of their questioning?

Women's Rights: Just as France was having a revolution for equality for all peoples, a strong women's rights movement was enveloping the nation. Olympe de Gouges, a main figure in this movement, stated in her "Declaration of the Rights of Woman and the Female Citizen" that women were born free and equal to men. English author Mary Wollstonecraft also penned a similar document entitled A Vindication of the Rights of Woman. She compared the unjust subordination of women under their husbands to the subordination of the French peasantry under the French aristocracy. Watch the video below for more information on women's suffrage in the United States:

Abolition of Slavery: At first, Enlightenment reasoning was commonly used to justify slavery. Scientists studied Africans and came up with lists of how they were biologically different than white people, which made it a "scientific fact" that blacks were inferior to whites. Also, since slavery helped the economies of nations as a whole, it was commonly viewed as good. Slavery was also a huge debate when composing the Constitution of the United States of America. Advocates for abolition included Alexander Hamilton, who ultimately lost the argument for the time being.
End of Serfdom: Russian serfs were emancipated beginning in 1861 under the rule of Alexander II. Groups of serfs were given land grants which one male was in charge of distributing to all the other serfs. Unfortunately, the 50 million ex-serfs were somewhat restricted by the requirements of communal landowning and decision making. Key figures in this liberation include educated serfs such as Alexander Nikitenko who protested their enslaved state.
Contract government: A major feature of the Enlightenment was the introduction of a contract government, or the "political theory that views government as stemming from the people, who agree to surrender a measure of personal freedom in return for a government that guarantees protection of citizens' rights and property" (Crossroads and Cultures). Up until this point, laws of a state were mainly based on the leading rulers' whims. Now, however, the people had a say in how they were to be governed. This is evident in the creation of the Constitution of the United States and other such documents.