I think it's already been made very clear that some people are naturally monogamous and that most people are naturally not. Even the survey here confirms that most people are not strictly monogamous and this is a site of mostly females who are notoriously more monogamous than males.
I agree, it's very unfair for people to assume you're only monogamous for one reason or another when it's possibly just your natural setting. I did post links to studies that includes stats such as:
"Out of 238 [human] societies around the world, only 43 are monogamous. And, throughout history there have been reports of wealthy and powerful men having hundreds, if not thousands, of concubines. This was accepted practice in past societies and the children from these unions were all considered legal and could inherit property."
I'll repost them for you:
http://www.livescience.com/32146-are-hu ... amous.htmlhttp://www.dailymail.co.uk/femail/artic ... veals.htmlhttp://www.sciencedaily.com/releases/20 ... 172244.htmhttp://www.huffingtonpost.com/2011/11/1 ... 87009.htmlhttp://www.theguardian.com/commentisfre ... y-researchhttp://www.healthcentral.com/sexual-hea ... -supposed/http://www.thenakedscientists.com/HTML/ ... n/1000085/One of those does go into detail about why monogamy is more prevalent in certain societal circumstances. Things including lack of resources and a prevalence of men who kill kids in order to have more mating opportunities and more resources for their own. It's possible that certain monogamous genes became more prevalent in areas where this was an issue because more children of monogamous people would have survived. One also goes into how weaker men would have preferred monogamous women because their children would have had a higher chance of survival and a higher likelihood of being theirs. It seems to be a trait more specific to europe. Even so, europe is not historically known for it's overall monogamy. Very interesting stuff in these scientific articles from the experts.