Equality. It is a word we all like to hear when we talk about gender differences. It is a word already used in the American declaration of independence, saying:

We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the Pursuit of Happiness.

Declaration of independence of the thirteen united States of America, July 4, 1776