Mayan culture probably collapsed as a result of incessant inter-city warfare combined with a long period of severe drought, according to modern sources. While they certainly performed plenty of bloody sacrifices they were for religious purposes, mainly related to rainfall and crop fertility. The majority of the victims were prisoners of war, often aristocrats from opposing cities. Any cannibalism I know of involved prisoners and was strictly ritualistic.
Considering the non-cannibalistic excesses of the Roman circus and the persecution of Christians and many others, it's hard for me to vioew the Maya as much more barbarous.
I know Jared Diamond isn't the most popular author around here but I tend to read, think, then judge. He makes some very good points, but I'll warn you in advance that Diamond and Fagan are both "global warming" advocates:
Comments posted to http://www.columbia.edu/~lnp3/mydocs/ecology/JaredDiamond2.htm on Jared Diamond's "Collapse: How Societies Choose to Fail or Succeed:"
Although Mayan society had endured drought over its thousand year history, there is evidence that the most severe drought coincides with the collapse. Although Diamond acknowledges that such droughts occurred, he thinks that they were only critical insofar as they coincided with "too many people" in a confined space.
What is missing from Diamond's analysis, however, is the *cause* of drought. One would think that an environmentalist would want to address this question. To discover the answer, you have to turn elsewhere. In particular, the work of anthropologist Brian Fagan is most instructive. In a series of books on ancient societies, he focuses on the role of El Niño-Southern California (ENSO) events in their collapse.
In his latest, titled "The Long Summer: How Climate Changed Civilization," Fagan points to the research done by climatologist David Hodell. By examining titanium traces in the waters off of Venezuela (a very precise way to measure droughts), Hodell concluded that a major ENSO event coincided with Mayan collapse. Archaeologist Dick Gill studied Swedish tree rings and came to similar conclusions.
Studying the evidence of Mayan ruins from this period, archaeologist Peter Harrison discovered evidence of cannibalism--a sure sign of a society driven to desperation. Another group of indigenous peoples, the Anasazi, whose social structures were similar to the Mayans, have also been connected to cannibalism. In their case, the findings have taken on a sensational aspect, especially when they are divorced from the climatological and economic circumstances that may explain them. In other words, cannibalism is not seen in the same terms as what happened to the Donner party, but rather as an expression of what Diamond termed "The Golden Age That Never Was."
The scholar most identified with this topic is Christy Turner II whose study "Man Corn" tries to explain Anasazi cannibalism as an early form of totalitarian control: [Poster’s Note: by the invading Toltecs from Mexico, it must be recalled, who are thought to have taken over the large ceremonial site at Chaco Canyon and who ruled the original inhabitants by terror.]
"Terrorizing, mutilating, and murdering might be evolutionarily useful behaviors when directed against unrelated competitors. And what better way to amplify opponents' fear than to reduce victims to the subhuman level of cooked meat, especially when they include infants and children from whom no power or prestige could be derived but whose consumption would surely further terrorize, demean, and insult their helpless parents or community? ... The benefits would be threefold: community control, control of reproductive behavior (that is, dominating access to women), and food. From the standpoint of sociobiology, then, cannibalism could well represent useful behavior done by well-adjusted, normal adults acting out their ultimate, evolutionarily channeled behavior. On the other hand, one can easily look upon violence and cannibalism as socially pathological."
Once again we find sociobiology trumping more useful forms of analysis based on objective economic factors. If you reduce humanity to being a "Third Chimpanzee" or "Naked Ape," naturally you will look for genetic dispositions to violence and subjugation instead of extreme distress brought on by climate or other socio-economic factors.
At least Diamond does not resort to such essentialist nonsense when trying to understand Anasazi collapse. Once again the main culprit is deforestation and unwise farming practices, but exacerbated by a drought that just seems to come and go with the seasons.
Once again you have to turn to Brian Fagan for a more satisfactory explanation of why such a devastating drought occurred. He states that the same ENSO events that struck the Yucatan peninsula also struck the American southwest. When crops failed and water disappeared, cannibalism did occur--although the exact extent is difficult to establish.