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Drive to rein in bullies led to evolution of morality, study proposes

March 30, 2005
Courtesy 
and World Science staff

Peo­ple may be­have mor­ally and help each oth­er be­cause our dis­tant an­ces­tors learn­ed to band to­geth­er to con­trol bul­lies, a new study pro­poses.

The re­search takes aim at one of the cen­tral puz­zles in ev­o­lu­tion­ary bi­ol­o­gy: why hu­mans help each oth­er even when there is no ap­par­ent ben­e­fit in do­ing so.

Al­tru­ism, the sac­ri­fice of in­di­vid­ual gains for the great­er good, seems at first glance to flout the “sur­vival of the fittest” prin­ci­ple crit­i­cal to ev­o­lu­tion­ary the­o­ry. Evo­lu­tion states that spe­cies grad­u­ally change be­cause each spe­cies’ best-functioning mem­bers con­tin­u­ally spread their genes through a popula­t­ion, at the ex­pense of weaker mem­bers’ genes. The popula­t­ion grad­u­ally changes as a re­sult. But as al­tru­ism of­fers no ap­par­ent ben­e­fit to the al­tru­ist, it would seem few or no “al­tru­ism genes” should ex­ist.

In the new stu­dy, math­e­ma­ti­cian and bi­ol­o­gist Ser­gey Gav­ri­lets of the Uni­vers­ity of Ten­nes­see, Knox­ville, pro­poses that dis­tant an­ces­tors of hu­mans might have seen lit­tle cost and con­si­der­able gain to be had by help­ing to de­fend vic­tims of bul­lies. The ben­e­fit could arise be­cause eve­ry­one would be bet­ter off with­out the bul­ly­ing. In time, this might have led to a more gen­er­al­ized help­ing in­stinct.

Al­though sev­er­al the­o­ries have arisen to ex­plain al­tru­ism, none are “di­rectly ap­pli­ca­ble to the emer­gence of egal­i­tar­ian be­hav­ior in hi­er­ar­chic­ally or­gan­ized groups that char­ac­ter­ized the so­cial life of our an­ces­tors,” Gav­ri­lets wrote, re­port­ing his re­search in this week’s early on­line is­sue of the jour­nal Pro­ceed­ings of the Na­tio­n­al Aca­de­my of Sci­en­ces.

By band­ing to­geth­er against bul­ly­ing, “it is pure self­ish ten­den­cies that could drive the emer­gence of help­ing be­hav­ior, em­pa­thy, and mor­al val­ues,” Gav­ri­lets wrote. The ben­e­fits come be­cause the strongest and dom­i­nant mem­ber of a so­ci­e­ty can of­ten bully his way in­to gain­ing a vastly dis­pro­por­tion­ate share of the re­sources—in­clud­ing mat­ing op­por­tun­i­ties, he not­ed. This in­e­qual­ity harms eve­ry­one else and pro­vides a pow­er­ful in­cen­tive for the weaker com­peti­tors to take mat­ters in­to their own hands. But that is a task best not tak­en on alone.

“The mech­an­ism stud­ied here is very pow­er­ful,” he added, “in that it does not re­quire re­lat­ed­ness, group se­lec­tion, re­cipro­city, or reputa­t­ion.” Group se­lec­tion is the con­cept that ev­o­lu­tion can op­er­ate on the lev­el of whole groups rath­er than only in­di­vid­uals.

Gavrilets sug­gests that the ben­e­fits that come from tak­ing down a bully are rel­a­tively di­rect com­pared to, say, do­ing some­thing nice be­cause you’re hop­ing the re­cip­i­ent will re­turn the fa­vor—a fac­tor in some oth­er the­o­ries on how help­ing evolved. Gav­ri­lets pro­posed a math­e­mat­i­cal mod­el in the pa­per to show how an­ti-bul­ly­ing coali­tions could be­come ef­fec­tive and es­tab­lish them­selves.

“When ever­ybody acts to en­force equal­ity among all oth­er mem­bers of the group, a group-lev­el equal­ity de­vel­ops,” he wrote. “Once the ten­den­cies for egal­i­tar­ian­ism… are well grounded in genes, they can be elab­o­rat­ed and aug­ment­ed by cul­tur­al norms.”

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People behave morally and help each other in large part because our distant ancestors learned to band together to control bullies, a new study proposes. The research takes aim at one of the central puzzles in evolutionary biology: why humans help each other even when there is no apparent benefit in doing so. Altruism, the sacrifice of individual gains for the greater good, seems at first glance to flout the “survival of the fittest” principle critical to evolutionary theory. That theory states that species gradually change because each species’ best-functioning members continually spread their genes through a population, at the expense of weaker members’ genes. The population gradually changes as a result. But as altruism offers no apparent benefit to the altruist, it would seem few or no “altruism genes” should exist. In the new study, mathematician and biologist Sergey Gavrilets of the University of Tennessee, Knoxville, proposes that distant ancestors of humans might have seen little cost and considerable gain to be had by helping to defend victims of bullies. The benefit could arise because everyone would be better off without the bullying. In time, this might have led to a more generalized helping instinct. Although several theories have arisen to explain altruism, none are “directly applicable to the emergence of egalitarian behavior in hierarchically organized groups that characterized the social life of our ancestors,” Gavrilets wrote, reporting his research in this week’s early online issue of the journal pnas. By banding together against bullying, “it is pure selfish tendencies that could drive the emergence of helping behavior, empathy, and moral values,” Gavrilets wrote. The benefits come because the strongest and dominant member of a society can often bully his way into gaining a vastly disproportionate share of the resources—including mating opportunities, he noted. This inequality harms everyone else and provides a powerful incentive for the weaker competitors to take matters into their own hands. But that is a task best not taken on alone. “The mechanism studied here is very powerful,” he added, “in that it does not require relatedness, group selection, reciprocity, or reputation.” Group selection is the concept that evolution can operate on the level of whole groups rather than only individuals. Gavrilets suggests that the benefits that come from taking down a bully are relatively direct compared to, say, doing something nice because you’re hoping the recipient will return the favor—a factor in some other theories on how helping evolved. Gavrilets proposed a mathematical model in the paper to show how anti-bullying coalitions could become effective and establish themselves. “When everybody acts to enforce equality among all other members of the group, a group-level equality develops,” he wrote. “Once the tendencies for egalitarianism… are well grounded in genes, they can be elaborated and augmented by cultural norms.”