conspecific killings in chimpanzees and humans

conspecific violence in humans / chimpanzees

Animals other than humans engage in lethal aggression, including organized, inter-communal attacks. Lethal aggression can be understood naturally as an extreme result of biological programs, interests, and conditions that generally produce aggression among animals. There’s no good reason for thinking that humans invented lethal aggression or that other animals engage in lethal aggression only as a result of human impact.[1]

The over-all sex ratio of killings of humans in the U.S. today is similar to that among chimpanzees. Across many years of observing chimpanzee communities, inter-communal chimp killings (observed and inferred) of weaned victims comprised 32 males and 8 females.[2] The sex ratio of victims in chimpanzee killings (four males per female) is nearly the same as that among human adults killed by interpersonal violence within the U.S. Males are highly disproportionately represented among adults killed among both humans and chimpanzees.

Humans and chimpanzees differ sharply in the distribution and sex ratios of adult inter-communal and intra-communal killings. Inter-communal killings (observed and inferred) of weaned chimpanzee victims comprised 23 males and 6 females.  The corresponding numbers for intra-communal killings were 9 male and 2 female chimpanzee victims.[3]  About three times as many adult chimpanzee killings are inter-communal, while the killing sex ratio is about equally four males per female for inter-communal and intra-communal adults killed. Chimpanzee adult killings are predominately directed toward extra-communal others without additional sex differentiation.

Compared to chimpanzees, the killing of adult humans in the U.S. today is much more intra-communal. For U.S. persons the ratio of inter-communal killings to intra-communal killings is about 0.05.[4] Accounting for persons of other communities that the U.S. military kills would probably tip the killing distribution to inter-communal killings. But that’s in part an artifact of vastly superior U.S. military technology for killing others. Across all nations, the ratio of inter-communal killings relative to intra-communal killings is probably considerably less than the chimpanzee ratio of three inter-communal killings per intra-communal killing.

Compared to chimpanzees, inter-communal human killings are strongly skewed toward adult males. Within the U.S., about 4 men are killed per woman killed. Among U.S. military personnel on active duty, about 40 men are killed per woman killed. Accounting for the persons that U.S. military personnel kill would probably raise the relative prevalence of killing men even higher.[5] The sex ratio of humans killed differs greatly for inter-communal killings relative to intra-communal killings.

A simple, adaptive explanation of killings is that “killing is a means to eliminate rivals when the costs of killing are low.” Within a community, more individuals are more exposed to each other and more directly rivals. On the other hand, killings within a community undermine the social solidarity and trust necessary for communal living. Adult males tend to be more vigorous rivals with each other for sexual opportunities. Adult females are more vigorous rivals with each other for opportunities to have resources transferred to them. The simple, adaptive explanation doesn’t go far toward explaining the intra-communal / inter-communal killing distribution, the killing sex ratio, and the relationship between the two.[6]

Humans are highly skilled in deluding themselves about objective realities of violence.  Consider these incontestable facts for the U.S.:

Humans seem socially incapable of bringing to reason these basic facts about killing humans. Complex social dynamics seem to shape both killings of humans and social understanding of those killings.

Complex social dynamics may also govern killings among chimpanzees. Looking for such patterns among chimpanzees may help humans to better understand themselves.

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[1] John Horgan at Scientific American’s Cross-Check has hosted a tedious dialogue about the question:

Is chimpanzee violence a product of nature or nurture? Genes or environment?

Nature and nurture are intimately related. The expression of genes depends on the environment. The environment, social interaction, and nurture depend on genes. The construct “nature or nurture” is an ideological construct useful for mobilizing political instincts and seeking attention in mass media. It’s intellectually worthless.

Whether human impact is prompting chimpanzees to kill each other is an interesting scientific question. Wilson et al. (2014) provides good reason to think that human impact has had little to do with chimpanzees killing each other (see also additional explanation). However, the vast majority of book and magazine readers believe strongly that humans should lessen their impact on surviving chimpanzee and bonobo populations.  Associating unattractive events (killings) with human impact, like describing males as demonic, is a compelling content-marketing strategy.

[2] Counted from Wilson et al. (2014) Extended Data Tables 1 & 3.

[3] Id.

[4] Deaths by sex of U.S. military personnel on active duty serving in wars in Afghanistan and Iraq since 2001 amounts to 6,664 men and 161 women. In comparison, in the U.S. in 2010 among men and women ages 18 to 40, 8,242 men and 1,531 women were homicide victims.  The ratio is calculated as the average across 13 years of the Afghanistan / Iraq U.S. military death total relative to the within-U.S. homicide total in 2010.

[5] On Sept. 30, 2008, 14.3% of active duty military personnel were female. Adjusting for this active duty sex share, the death rate for men is 6.7 times higher than for women. Willingness to serve on active duty in the U.S. volunteer/paid military is behaviorally significant and sex differentiated.

[6] The quoted definition of the adaptive explanation (“adaptive hypothesis”) is from Wilson et al. (2014) p. 416.  Id. notes, “chimpanzees could potentially attack members of their own community on a daily basis, but rarely encounter members of other communities.” That makes the chimpanzee intra-communal /inter-communal killing distribution all the more remarkable relative to the U.S. today. Wrangham, Wilson & Muller (2006), which compares chimpanzees to human subsistence societies, offers little insight into the intra-communal /inter-communal killing distribution and the killing sex ratio for adults.

[7] See note 4.


Wilson, Michael L., Christophe Boesch, Barbara Fruth, Takeshi Furuichi, Ian C. Gilby, Chie Hashimoto, Catherine L. Hobaiter, et al. 2014. “Lethal aggression in Pan is better explained by adaptive strategies than human impacts.” Nature. 513 (7518): 414-417.

Wrangham, Richard W., Michael L. Wilson, and Martin N. Muller. 2006. “Comparative rates of violence in chimpanzees and humans.” Primates. 47 (1): 14-26.

Hrotsvit of Gandersheim on men in the Life of Saint Thais

imagined portrait of Hrotsvit of Gandersheim

Inciting men to fight with each other and requiring men to provide goods to women for sex are central features of gynocentric social organization across societies and throughout history. The life of Saint Thais in early Greek, Syriac, and Lain sources briefly described gynocentric social organization:

There was a certain harlot called Thais. She was so beautiful that many men for her sake sold all that they had and reduced themselves to utter poverty. Quarrels arose among her lovers and often the doorsteps of this girl’s house was soaked in the blood of young men.[1]

Thais became rich from collecting goods from men for having sex with her. With  the help of Abba Pafnutius, a leading Egyptian desert father, Thais repented her sins. She begged God, “You who have made me, have pity on me.”[2] This God-created, Godly woman became a saint widely honored for over a millennium in Christian churches in western Eurasia.

The gynocentric social organization that holds men subservient to women hasn’t been reformed. Although Christian theology affirms that God made man, it hasn’t affirmed with social effectiveness that God made men. The materially, sexually, and physically impoverished and injured men in the story of Saint Thais haven’t been socially redeemed. They hardly attract any social interest. Throughout history, the lives of the vast majority of men have been of social interest only as means for providing goods for others or for fighting with other men.

The tenth-century thinker and playwright Hrotsvit of Gandersheim provided an under-appreciated critical perspective on gynocentric social organization. Hrotsvit of Gandersheim was an elite woman religious closely connected to the royal Germanic courts of Otto the Great and Otto II.[3] Hrotsvit didn’t use her privileged position to push for more privilege for herself and women like her. Hrotsvit instead rewrote the story of Thais as a play that subtly criticizes men’s oppression and urges a more harmonious social organization that provides justice for men.

In Hrotsvit’s dramatization, Thais explicitly recognizes the injustice she had done to men. The men who love Thai are utterly subservient to her despite her exploitation of them. She contemptuously goads them, “Come, hurry along, / my worthless lovers’ throng!” The men grovel in response, “The voice of Thais calls us, let us hurry, let us go / so that we don’t offend her by being slow.” These men are incapable of asserting their own right to justice. To provide justice to them, Thais destroys the exchange values that subordinate them. She declares:

All that I extorted from you unjustly, I now wish to burn,
so that no spark of hope is left that I will ever again return
and give in to your lust. [4]

Thais doesn’t seek to suppress men’s lust. She sets men free from the market through which their lust enslaves them.

Hrotsvit implicitly represents the impossibility of changing womanly nature. Both Thais and Pafnutius describe Thais as burning already refined gold. Gold cannot be burned away. Gold is reshaped in fire.[5] Thais’ life of luxury and sexual pleasure is reformed by having her live in a barren cell in the stench of her excrement.[6] Hrotsvit’s drama doesn’t transform Thais from a woman into some other type of being. It enacts a reshaping and re-balancing of Thais’ womanly nature.[7]

As a man, Pafnutius both laments men’s injuries and figures men as beasts. Pafnutius dilates upon the prior description of Thais’ exploitation of men:

Crowds of lovers flock to her, wishing to be near … These fools that come to her are blind in their hearts; they contend and quarrel and fight each other. … Then, when the fight has started they fracture each other’s faces and noses with their fists; they attack each other with their weapons and drench the threshold of the brothel with their blood gushing forth. … This is the injury to our Maker which I bewail. / This is the cause of my grief and ail.[8]

Pafnutius doesn’t act to help men directly. Like the crowds of Thais’ lovers, his attention focuses on Thais. He acts boldly to rescue Thais. He takes her to a woman leader of noble, holy virgins, an abbess. He tells the abbess:

I have brought you a half-dead little she-goat, recently snatched from the teeth of wolves. I hope that by your compassion its shelter will be insured, and that by your care, it will be cured, and that having cast aside the rough pelt of a goat, she will be clothed with the soft wool of the lamb.[9]

Thais is conveyed with compassion. Men, in contrast, are figured as wolves attacking her with their teeth. Wounded men quickly vanish in men’s communication with women. Men without the help of women will not help men.

Hrotsvit, the Strong Voice of Gandersheim, concludes her dramatization of Thais’ reformation with her wisdom silently rising through Pafnutius’ prayer. Pafnutius prays for Thais at the hour of her death:

Thou Who created man, unlike Thee, to consist of diverse substances;
grant that the dissolving, diverse parts of this human being
may happily return to the source of their original being;
that the soul, divinely imparted, live on in heavenly bliss,
and that the body may rest in peace
in the soft lap of earth, from which it came,
until ashes and dirt combine again
and breath animates the revived members;
that Thais be resurrected exactly as she was,
a human being, and joining the white lambs may enter eternal joy.[10]

Pafnutius recognizes the God-created, earthly goodness of Thais. He prays that she be resurrected “exactly as she was, a human being.”

Above Pafnutius’ focus on Thais is Hrotsvit’s understanding that men, like Thais, are human beings. Men are neither wolves nor demons. Men in their masculinity are as God-created as women are. Man, male and female God created them, consists of diverse substances. Man, women and men, has a unity within God’s creation of human being. Hrotsvit, the Strong Voice of Gandersheim, carries forward the prophetic mantle of Elijah.[11] The final act of her play is for her audience to enact. We must appreciate men exactly as they are, human beings.[12]

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[1] From English translation of the Life of Saint Thais the Harlot in a Latin translation of a Greek text by an anonymous author of the fourth or fifth century GC, adapted from Ward (1987) p. 83. Early Greek texts attributed Thais’ conversion to Sarapion the Sindonite rather than Pafnutius (Paphnutius). Kuehne (1922) p.  12. On the early texts of the conversion of Thais (Thaïs), id. pp. 12-45 and Ward (1987) pp. 76-82. Engle (2006) pp. 5-10 describes additional medieval references. A life of Saint Thais appears in the Northern Homily Collection from northern England early in the fourteenth century. Whatley, Thompson & Upchurch (2004) collates the manuscripts and provides the text. A early fourteenth-century life of Saint Thais also exists in middle English in British Library MS Harley 2253.

[2] Cf. Isaiah 64:8. In the early surviving life, a Latin translation of a Greek text, Pafnutius instructs Thais to say those words of prayer. Trans. Ward (1987) p. 84. In Hrotsvit of Gandersheim’s Thais, Thais says those words unprompted. From Latin trans. Wilson (1989) ll. 812-3, modernized English.

[3] Hrotsvit is also commonly spelled Hrotsvitha, Hroswitha, and Roswitha. On her elite status, Dronke (1984) pp. 55-60.

[4] Hrotsvit of Gandersheim, Thais, ll. 461-3, from Latin trans. Wilson (1989). The previous two quotes are from ll. 441-4. Wilson’s translation is also available in Wise and Walker (2003).  All subsequent quotes from Hrotsvit’s Thais are from Wilson’s translation. Hrotsvit’s Latin text is available online in Strecker (1906).

[5] Pafnutius’ and Thais’ descriptions of substantial change, ll. 425-38, seem best read ironically. On Hrotsvit’s subtlety, Dronke (1984) pp. 71-83.

[6] Pafnutius reforms Thais with “medicine of contraries” (ll. 546-7). He explains, “It is only right / that you expiate the evil sweetness of alluring delight / by enduring this terrible smell.” ll. 599-601. Whatley, Thompson & Upchuarch (2004) describe the early Latin text:

Thaïs is sealed into a monastic cell and when she asks the monk where she is to urinate he charitably responds, “In the cell, as you deserve.”

The sarcasm of “charitably” evinces lack of understanding and prevailing misandry. Wise & Walker (2003), p. 191, imposes modern, dark-age dogma on the conversion of Thais. With her elaboration of the “medicine of contraries,” Hrotsvit of Gandersheim was a more broad-minded, humane, and sophisticated reader of the ancient life of Thais. On the other hand, living in an enclosed space filling with their own excrement doesn’t seem to be effective medicine for scholars today.

[7] Wailes (2006), p. 188, makes this important point:

The philosophical ideas of harmony throughout creation, presented in the first dialogues, oblige readers to interpret the sinfulness of Thais not as the triumph of evil but as an imbalance or discord between parts of her created being. Hrotsvit looks at this woman, who acts as a volcano of lust, and is no more horrified or dismayed than is Pafnutius.

[8] ll. 256-7, 259-61, 263-7, 269-70. I’ve omitted the responses of Pafnutius’ disciples. In a burlesque of student behavior, the disciples echo and affirm Pafnutius’ statements.

[9] ll. 529-35. Referring to Thais as a goat connotes her high propensity for sexual activity. Insightful scholarship on Hrotsvit’s Thais hasn’t adequately appreciated medieval women’s vigorous sexuality:

Hrotsvit’s Thais became a prostitute because of her love of money. The root of her immorality is avarice, which, in combination with her great beauty, resulted in her choice of prostitution as a career.

Wailes (2006) p. 185. Thais’ lovers, however, describe Thais as “She, who never thought of anything but love-making, / And gave herself over to pleasure completely!” ll. 480-2, trans. id.  The historically male voice of blaming men for women’s choices has dominated scholarship in recent decades. For example, the blurb for Karras (1996) tells the stories of the lives of women prostitutes: “their entrance into the trade because of poor job and marriage prospects or because of seduction or rape.” That women might choose to prostitute themselves for relatively easy earnings or for their sexual interests can only be considered at the margins of orthodox scholarship. Cf. De Jour (2005).

[10] ll. 817-28.  In her Preface to her plays, Hrotsvit refers to herself as the “Strong Voice of Gandersheim.” Dronke insightfully observes:

With her ironically placed Latin equivalent for her name — Clamor Validus = Old Saxon Hrôthsuith —  she even intimates that writing chaste, Christian plays in the Terentian genre, and thereby redeeming the genre, was a kind of prophetic mission she took on. Hers is the ‘mighty voice’ {‘strong voice’}: the expression ‘ego Clamor Validus’ can hardly help carrying a reminiscence of John the Baptist’s ‘ego vox clamantis’. At the same time, clamor can have an objective as well as subjective force: then her Latinization of the name would suggest something more like ‘the big noise of Gandersheim,’ and be a self-mocking recognition that the spreading rumor of her composing was making her known as a prodigy — or a freak.

Dronke (1984) p. 70. Hrotsvit’s prophetic mission was far more important and challenging than redeeming the Terentian genre.

[11] Cf. Genesis 1:27, 2:23; 1 Kings 19:12.

[12] Zampelli (2013) insightfully explores Hrotsvit’s theatricality and Christian commitments:

Her texts bear witness to an understanding of performance in which “entertainment” coincides with “efficacy,” where the aim of the dramatic action is not only to delight but also to transform the audience. … In her plays, Hrotsvit aims to effect changes in her audience, encouraging them to hold in their own bodies the action mediated by her dramatic compositions.

Id. pp. 156, 158. Zampelli, like scholarship on Hrotsvit in general, seems yet to be transformed by Hrotsvit’s concern for men.

[image] Imagined portrait of Hrotsvit of Gandershiem. Engraved plate from Johann Georg Leuckfeld, Antiquitates Gandersheimenses, Wolfenbuttel, 1709, reproduced in Haight (1965). The seventeenth-century scholar Martin Friedrich Seidel claimed that Hrotsvit was an anagram for Helena van Rossow, a member of the Brandenburg von Rossow family. Wilson (1998) p. 4. The engraving reflects that attribution.


De Jour, Belle. 2005. The intimate adventures of a London call girl. London: Weidenfeld & Nicolson.

Dronke, Peter. 1984. Women writers of the Middle Ages: a critical study of texts from Perpetua († 203) to Marguerite Porete († 1310). Cambridge: Cambridge University Press.

Engle, Sidney Douglas. 2006. A study of the Thaïs legend with focus on the novel by Anatole France. Thesis (M.A.)–University of Tennessee, Knoxville, 2006.

Haight, Anne (Lyon). 1965. Hroswitha of Gandersheim; her life, times, and works, and a comprehensive bibliography. New York: Hroswitha Club.

Karras, Ruth Mazo. 1996. Common women: prostitution and sexuality in Medieval England. New York: Oxford University Press.

Kuehne, Oswald Robert. 1922. A study of the Thaïs legend with special reference to Hrothsvitha’s “Paphnutius.” Ph.D. Dissertation. University of Pennsylvania.

Strecker, Karl, ed. 1906. Hrotsvithae Opera. Lipsiae: In aedibus B.G. Teubneri.

Wailes, Stephen L. 2006. Spirituality and politics in the works of Hrotsvit of Gandersheim. Selinsgrove: Susquehanna University Press.

Ward, Benedicta. 1987. Harlots of the desert: a study of repentance in early monastic sources. Kalamazoo, Mich: Cistercian Publications.

Whatley, E. Gordon, Anne B. Thompson, and Robert Upchurch, eds. 2004. “The Life of Saint Thaïs.” Ch. IV in Saints’ Lives in Middle English Collections. Kalamazoo, Mich: Published for TEAMS (The Consortium for the Teaching of the Middle Ages) in association with the University of Rochester by Medieval Institute Publications, College of Arts & Sciences, Western Michigan University.

Wilson, Katharina M., trans. 1989. The plays of Hrotsvit of Gandersheim. New York: Garland Pub.

Wilson, Katharina M. 1998. Hrotsvit of Gandersheim: a florilegium of her works. Woodbridge, Suffolk: D.S. Brewer.

Wise, Jennifer, and Craig Stewart Walker, eds. 2003. The Broadview anthology of drama: plays from the Western theatre. Vol I. Peterborough, Ont: Broadview Press.

Zampelli, Michael A. 2013. “The Necessity of Hrotsvit: Evangelizing Theatre.” Pp. 147-199 in Phyllis Rugg Brown and Stephen L. Wailes, eds. A companion to Hrotsvit of Gandersheim (fl. 960): contextual and interpretive approaches. Leiden: Brill.

gender equality and anti-men gender bigotry

tree, hollow inside, collapsed

Dying in military service on behalf of one’s country is a highly significant sacrifice. In U.S. military action in Afghanistan and Iraq since 2001, the sex ratio among U.S. military personnel killed on active duty is 41.4 men killed per woman killed. The sex ratio among U.S. military personnel wounded in action is even more unequal: 50.4 men wounded per woman wounded.[1]

Discussion of gender equality typically focuses on highly privileged positions. Politicians and news media celebrate affirmative efforts to foster gender equality among members of parliaments and corporate boards, CEOs, leading engineers and scientists, and other rich, powerful, or otherwise privileged persons. The theory seems to be that gender equality imposed at the top will trickle down to the vast mass of ordinary folk. Gender inequality in persons dying for their country seems to be of no more public interest than remedying explicit gender discrimination in the imposition of Selective Service obligations. Pushing for gender equality with only concern for women is a farce. Yet such efforts are prevalent. They face almost no serious challenge in public deliberation.

The most serious challenge to gender equality meaning anti-men gender bigotry is the demoralization of men. Men are being imprisoned for not being able to fulfill onerous financial obligations imposed on them for doing nothing more than having consensual sex. Men are being treated as presumptively criminal when accused of rape. Men are deprived of their children through family courts administered with acute anti-men gender bias. The demonization of persons who raise their voices about such injustices makes clear to men that their lives matter little in competition for public attention and public influence.

Men treated as second-class citizens will not work hard. Men treated as second-class citizens will not fight hard.  That is the fundamental challenge for the U.S., for Europe, and for other countries seeking to follow the current world-elite consensus.[2] Financial machinations and immigration can help to offset domestic economic and demographic stagnation. Countries can pretend that their security is assured with the quintessential feminine weapon: nuclear bombs. These machinations and delusions won’t change the demoralizing reality that today in the Western world gender equality actually means anti-men gender bigotry.

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Data: U.S. military personnel, by sex, killed and wounded in active duty in Iraq and Afghanistan conflicts (Excel version).

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[1] See the U.S. military casualties by sex dataset.  More comprehensive measures of casualties also show strong biases toward men’s deaths. In Iraq during the two years preceding the start of war in 2003, Iraqi men’s death rate was about twice that of Iraqi women’s. War in Iraq caused men’s death rate to rise much more sharply than women’s. See Hagopia et al. (2013) p. 8, Fig. 3. At the peak of the war period (2005-2006), Iraq men’s death rate was about 2.5 times that of women. In the period after the U.S. began fighting in Iraq through 2011, 8.5 males died from violence for each female that died from violence. Id. p. 7. U.S. military action targets men for killing. Drone strikes target men after they have left their homes or when they are living without their loved ones. Drone strikes seek to kill a specific man, but not his wife and other women who intimately support him and love him. Drone strikes are probably interpreted as a grave insult to women in traditional cultures that retain a more humane and reasonable understanding of gender equality than does the U.S.

[2] World elite leaders fly into places like Iraq and Afghanistan and lecture local leaders on empowering women and girls. Then they seek to train and equip local men in the brutal business of fighting highly motivated, viciously inhumane enemy forces. Not surprisingly, local men seem not to appreciate the motivating power of Western ideals of truth, equality, and human dignity. Perhaps they perceive the reigning Western anti-men gender bigotry.

[image] Douglas Galbi’s photograph in Rosslyn, VA.


Hagopian, Amy, Flaxman, Abraham D., Takaro, Tim K., Esa Al Shatari, Sahar A., Rajaratnam, Julie, Becker, Stan, Levin-Rector, Alison, et al. 2013. “Mortality in Iraq Associated with the 2003–2011 War and Occupation: Findings from a National Cluster Sample Survey by the University Collaborative Iraq Mortality Study.” PLOS Medicine 10:10. DOI: 10.1371/journal.pmed.1001533