"Long before it's in the papers"
April 05, 2016


Human sacrifice promoted class divisions where it occurred, study finds

April 5, 2016
Courtesy of Nature
and World Science staff

The rit­u­al hu­man sac­ri­fice that used to take place in many so­ci­eties tended to pro­mote class di­vi­sions, a new study sug­gests.

The re­search, pub­lished on­line the jour­nal Na­ture this week, con­cludes that the grisly prac­tice played a role in sus­tain­ing and build­ing so­cial stratifica­t­ion.

This im­age comes from a Span­ish doc­u­ment of the mid-1500s paint­ed in Cen­tral Amer­i­ca, de­scrib­ing con­tem­po­rary hu­man sac­ri­fice and other ri­tuals. The paint­ings in the doc­u­ment, known as the Co­dex Ma­gli­a­be­chi­a­no, are be­lieved to have been made by lo­cal artists com­mis­sioned by Span­ish priests who ac­com­pa­nied con­quer­ing Span­ish armies. Ac­cord­ing to the doc­u­ment, the im­age shows an "Az­tec priest per­form­ing the sac­ri­fi­cial of­fer­ing of a liv­ing hu­man's heart to the war god Hui­t­zi­l­o­poch­t­li." (Cour­te­sy U.S. Li­brary of Con­gress)

“Our re­sults re­veal a darker link be­tween re­li­gion and the ev­o­lu­tion of mod­ern hi­er­ar­chi­c so­ci­eties,” wrote the au­thors of the stu­dy, pub­lished this week on­line in the re­search jour­nal Na­ture.

Ev­i­dence of hu­man sac­ri­fice—the rit­u­al­ized kill­ing of some­one in or­der to plac­ate or please a god or gods—is scat­tered through­out the ar­chae­o­log­i­cal, ethno­graph­i­cal and writ­ten rec­ord. 

And while no so­ci­eties are known to openly prac­tice it to­day, re­ports of twisted, cult-related mur­ders linked to some sac­ri­fi­cial pre­text still emerge from time to time.

Why some so­ci­eties prac­tice sac­ri­fice has been a sub­ject of “en­dur­ing de­bate” among schol­ars, wrote the au­thors of the new stu­dy, Jo­seph Watts of the Un­ivers­ity of Auck­land in Aus­tral­ia and col­leagues. 

“The prac­tice has been con­jec­tured to act as a form of so­cial ca­thar­sis, a jus­tifica­t­ion for po­lit­i­cal con­flicts, and, when com­bined with can­ni­bal­ism, a means of over­com­ing pro­tein short­ages,” they wrote.

Some ar­chae­o­lo­gists have pro­posed a “so­cial con­trol” hy­poth­e­sis, they added. Ac­cord­ing to this idea, the sac­ri­fice acts as a way to jus­ti­fy class-based pow­er dis­tinc­tions be­cause it of­fers a su­per­nat­u­ral pre­text for the “ul­ti­mate” dis­play of au­thor­ity—tak­ing a life.

Watts and col­leagues an­a­lyzed a database of 93 tra­di­tion­al Aus­tro­ne­sian so­ci­eties, a family of cul­tures found in the ar­eas of the Pa­cif­ic and In­di­an oceans, where hu­man sac­ri­fice was not un­com­mon. The so­ci­eties span a large range of so­cial struc­tures, from sim­ple egal­i­tar­ian so­ci­eties to com­plex, hi­er­ar­chi­c ones, and en­vi­ron­ments, from small is­lands to con­ti­nents. 

The os­ten­si­ble rea­sons or oc­ca­sions for hu­man sac­ri­fice in these so­ci­eties, Watts and col­leagues wrote, of­ten in­clud­ed “the breach of ta­boo or cus­tom, the fu­ner­al of an im­por­tant chief, [or] the con­secra­t­ion of a newly built house or boat.”

For each cul­ture, the au­thors rec­orded the pres­ence or ab­sence of hu­man sac­ri­fice and rat­ed the lev­el of so­cial stratifica­t­ion. They then built mod­els to test the co-ev­o­lu­tion of hu­man sac­ri­fice and so­cial hi­er­ar­chy. Their find­ings: hu­man sac­ri­fice in­creased the chances of high so­cial stratifica­t­ion aris­ing, and of stay­ing in place once estab­lished.

Based on this, the au­thors sug­gest that re­li­gious rit­u­als had a role in the ev­o­lu­tion of mod­ern, com­plex so­ci­eties. They fur­ther pro­pose that rit­u­al kill­ing may have helped hu­mans tran­si­tion from the small, egal­i­tar­ian groups of our an­ces­tors to the large strat­i­fied so­ci­eties we live in to­day.

* * *

Send us a comment on this story, or send it to a friend

y Sign up for

On Home Page         


  • Hu­man sacri­fice pro­moted class divi­sions where it occur­red, study finds

  • My­ths of black tough­ness may contri­bute to pain under­treatment


  • Study links global warming, war for first time—in Syria

  • Smart­er mice with a “hum­anized” gene?

  • Was black­mail essen­tial for marr­iage to evolve?

  • Plu­to has even cold­er “twin” of sim­ilar size, studies find


  • F­rog said to de­scribe its home through song

  • Even r­ats will lend a help­ing paw: study

  • D­rug may undo aging-assoc­iated brain changes in ani­mals

The ritual human sacrifice that used to take place in many societies tended to promote class divisions, a new study suggests. The research, published online the journal Nature this week, concludes that the grisly practice played a role in sustaining and building social stratification. “Our results reveal a darker link between religion and the evolution of modern hierarchical societies,” wrote the authors of the study, published this week online in the research journal Nature. Evidence of human sacrifice—the ritualized killing of someone in order to placate or please a god or gods—is scattered throughout the archaeological, ethnographical and written record. And while no societies are known to openly practice it today, reports of twisted, cult-related murders linked to some sacrificial pretext still emerge from time to time. Why some societies practice sacrifice has been a subject of “enduring debate” among scholars, wrote the authors of the new study, Joseph Watts of the University of Auckland in Australia and colleagues. “The practice has been conjectured to act as a form of social catharsis, a justification for political conflicts, and, when combined with cannibalism, a means of overcoming protein shortages,” they wrote. Some archaeologists have proposed a “social control” hypothesis, they added. According to this idea, the sacrifice acts as a way to justify class-based power distinctions because it offers a supernatural pretext for the “ultimate” display of authority—taking a life. Watts and colleagues analyzed a database of 93 traditional Austronesian societies, a family of cultures found in the areas of the Pacific and Indian oceans, where human sacrifice was not uncommon. The societies span a large range of social structures, from simple egalitarian societies to complex, hierarchical ones, and environments, from small islands to continents. The ostensible reasons or occasions for human sacrifice in these societies, Watts and colleagues wrote, often included “the breach of taboo or custom, the funeral of an important chief, [or] the consecration of a newly built house or boat.” For each culture, the authors recorded the presence or absence of human sacrifice and rated the level of social stratification. They then built models to test the co-evolution of human sacrifice and social hierarchy. Their findings: human sacrifice increased the changes of high social stratification arising and prevented the loss of social stratification once it had arisen, they found. Based on these findings, the authors suggest that religious rituals had a role in the evolution of modern, complex societies. They further propose that ritual killing may have helped humans transition from the small, egalitarian groups of our ancestors to the large stratified societies we live in today. study finds