Many species of duck mate for life. That is their nature. Is lifelong monogamy innate to our species' nature?

Innate human nature is animalistic. If we were to go around mating with random humans as we please, STDs would run rampant, relationships would be meaningless, and overpopulation would be even more of a threat than it is now. Our human nature is the result of millions of years of evolution, but we've learned to live communally and altruistically faster than our own nature has caught up to us. Survival of the fittest was important way back when, but now that society is much more advanced, it's better to focus on helping out others than just helping ourselves. And thus breeding like crazy isn't as important as it used to be, but our nature hasn't really changed much. We've just learned how to live more effectively, safely, and less competitively. I hope this helps!