This documentary by the BBC looks at Scientific Racism, invented during the 19th century, an ideology that drew on now discredited practices such as phrenology and provided an ideological justification for racism and slavery. These theories ultimately led to eugenics and racial policies of the "master" race.

Herbert Spencer, the father of Social Darwinism as an ethical theory, was thinking in terms of elitist, "might makes right" sorts of views long before Darwin published his theory. However, Spencer quickly adapted Darwinian ideas to his own ethical theories. The concept of adaptation allowed him to claim that the rich and powerful were better adapted to the social and economic climate of the time, and the concept of natural selection allowed him to argue that it was natural, normal, and proper for the strong to thrive at the expense of the weak. After all, he claimed, that is exactly what goes on in nature every day.

However, Spencer did not just present his theories as placing humans on a parallel with nature. Not only was survival of the fittest natural, but it was also morally correct. Indeed, some extreme Social Darwinists argued that it was morally incorrect to assist those weaker than oneself, since that would be promoting the survival and possible reproduction of someone who was fundamentally unfit.

Social Darwinism was used to justify numerous exploits which we classify as of dubious moral value today. Colonialism was seen as natural and inevitable, and given justification through Social Darwinian ethics - people saw natives as being weaker and more unfit to survive, and therefore felt justified in seizing land and resources. Social Darwinism applied to military action as well; the argument went that the strongest military would win, and would therefore be the most fit. Casualties on the losing side, of course, were written off as the natural result of their unfit status. Finally, it gave the ethical nod to brutal colonial governments who used oppressive tactics against their subjects.