Great efforts have been made to conceal this fact.
Comparative ethnography can be carried out on a micro level: we can compare the cultures of North Dakota and South Dakota; we can compare the cultures of Graz and Linz.
We can also contrast cultures on a macro level: we can juxtapose Brazil with Sweden, or Burma with Japan.
Sometimes, we’ll even find that of two cultures, one or the other is “not better or worse, but simply different.” But that’s not always the case.
Well-intentioned but misguided educators have drilled several generations of students to say, of any social comparison, that various societies are “not better or worse, but simply different.”
In some cases, this is true: that the French produce more red wine, and the Germans more white wine, is an interesting difference, but not one which places a higher value on one or the other. The same is true of the comparison that people in northern Poland eat, on average, more seafood than those in southern Poland.
But in many cases, there is a valuative difference between cultures. ‘Valuative’ in this case refers to a state of affairs: a factual and descriptive evaluation.
A culture which regularly and largely denigrates women, restricts their personal and artistic expressions, denies them legal and political rights, permits and institutionalizes the physical and emotional abuse of women, denies them education, and generally relegates them to an inferior status, - such a culture is worse than a culture which usually does not do such things.
The same is true of race - where ‘race’ is understood to denote innate visible physical characteristics.
A society which structures itself in a manner calculated to minimize human creativity, and thereby eliminates not only much of academic education, but also largely reduces artistic expression in painting, music, and literature, and which so undermines the spirit of rational inquiry that the observational and empirical sciences not only fail to make progress, but rather retreat; a society which stunts the exercise of reason to the extent that higher mathematics and philosophy are neglected, and that those who pursue those disciplines are in danger of being persecuted; - such a society is worse than a society which allows the better and creative aspects of human nature to be developed.
As the International Baccalaureate Organization notes, scholars should “evaluate a range of points of view.”
The IBO is suggesting that differences not merely be observed and noted, but rather evaluated: values should be assigned.
A society which values human life generally, and each human life concretely, and which seeks to maximize individual political liberty for all its citizens, working to create “equal opportunity” and a “level playing field” for people to experiment, allowing them to seek or avoid risks and the rewards which follow them; a society which generally prefers peace to war - such a society is measurably and observably better than a society which seeks to confine and bind the human spirit.
Serious scholarship, examining the historical record, leads the reflective reader to conclude that some cultures are better than others.
[Postscript, January 2017: This post is deliberately provocative, but it is so in order to make this point: that one may not rationally evaluate one race to be better than another, or one gender to be better than the other. While one cannot assign superiority to any race or to either gender, and while one can also not assign inferiority to any race or to either gender, one can assign relative valuations to cultures. A culture which would disadvantage an individual based on the individual's race or gender is, ceteris paribus, inferior to a culture which does not so disadvantage individuals. This is clear in the original post above, but this postscript is added in response to correspondence from various readers.]