Cabin fever might set in quickly on Mars, and it might be contagious. Quarters would be tight. Governments would be fragile. Reinforcements would be seven months away. Colonies might descend into civil war, anarchy or even cannibalism, given the potential for scarcity. US colonies from Roanoke to Jamestown suffered similar social breakdowns, in environments that were Edenic by comparison. Some individuals might be able to endure these conditions for decades, or longer, but Musk told me he would need a million people to form a sustainable, genetically diverse civilisation.
What Would Happen If We Lived on Mars