martedì 16 maggio 2017

3 Il mito della gelosia

Secondo Christopher Ryan e Cacilda Jetha la tradizionale teoria del sesso fa acqua da tutte le parti e richiede una profonda revisione. Nel loro saggio “A Closer Look at the Standard Narrative of Human Sexual Evolution: ape in the mirror” provano ad impostarla. Ecco la loro tesi sulla natura libertina dell’uomo preistorico:
… Homo sapiens evolved to be shamelessly, undeniably, inescapably sexual. Lusty libertines. Rakes, rogues, and roués. Tomcats and sex kittens. Horndogs. Bitches in heat… these preconscious impulses remain our biological baseline, our reference point, the zero in our own personal number system… Willpower fortified with plenty of guilt, fear, shame, and mutilation of body and soul may provide some control over these urges and impulses…
Bisognerebbe tener conto di questa nostra natura profonda poiché rinnegarla produce costi non trascurabili.
… there are costs involved in denying one’s evolved sexual nature… They are paid in what E. O. Wilson called “the less tangible currency of human happiness that must be spent to circumvent our natural predispositions.”2 Whether or not our society’s investment in sexual repression is a net gain or loss is a question for another time….
Per comprendere meglio i punti deboli della teoria tradizionale bisogna prima mettere in chiaro cosa non si intende negare… 
… We don’t claim that men and women experience their eroticism in precisely the same ways, but as Tiresias noted, both women and men find considerable pleasure there. True, it may take most women a bit longer to get the sexual motor running than it does men, but once warmed up, most women are fully capable of leaving any man far behind. No doubt, males tend to be more concerned with a woman’s looks, while most women find a man’s character more compelling than his appearance (within limits, of course). And it’s true that women’s biology gives them a lot more to consider before a roll in the hay… Perhaps for many women libido is like the hunger of a gourmand. Unlike many men, such women don’t yearn to eat just to stop the hunger. They’re looking for particular satisfactions presented in certain ways. Where most men can and do hunger for sex in the abstract, women report wanting narrative, character, a reason for sex…
Ricostruiamo ora l’ortodossia partendo dai suoi quattro elementi di fondo…
… The relatively weak female libido Male parental investment (MPI) Sexual jealousy and paternity certainty Extended receptivity and concealed (or cryptic) ovulation
La narrazione ortodossa è incentrata sul concetto di famiglia e di contratto matrimoniale…
… The standard model posits that sexual exclusivity is crucial because in evolutionary times this was a man’s only way of ensuring his paternity. According to evolutionary psychology, this is the grudging agreement at the heart of the human family… Men offer goods and services (in prehistoric environments, primarily meat, shelter, protection, and status) in exchange for exclusive…
Tutto cio’ spiega bene l’attenzione femminile nel concedersi…
… So, if a woman becomes pregnant by a guy who has no intention of helping her through pregnancy or guiding the child through the high-risk early years, she likely is squandering the time, energy, and risks of pregnancy…
C’è un’economia sessuale sottesa a tutte le relazioni affettive, una visione proprietaria del corpo altrui che nasconde forme di prostituzione. Darwin dice sostanzialmente che vostra madre è una puttana…
… Steven Pinker calls this way of looking at human reproduction the genetic economics of sex: “The minimum investments of a man and a woman are…unequal,” explains Pinker, “because a child can be born to a single mother whose husband has fled but not to a single father whose wife has fled. But the investment of the man is greater than zero, which means that women are also predicted to compete in the marriage market, though they should compete over the males most likely to invest…”3 Conversely, if a guy invests all his time, energy, and resources in a woman who’s doing the nasty behind his back, he’s at risk of raising another man’s kids—a total loss… This is why evolutionary psychologists Margo Wilson and Martin Daly argue that men take a decidedly proprietary view of women’s sexuality… As attentive readers may have noted, the standard narrative of heterosexual interaction boils down to prostitution: a woman exchanges her sexual services for access to resources… The Adapted Mind, a book many consider to be the bible of the field, spells out the sex contract very clearly: A man’s sexual attractiveness to women will be a function of traits that were correlated with high mate value in the natural environment…. The crucial question is, What traits would have been correlated with high mate value? Three possible answers are as follows: The willingness and ability of a man to provide for a woman and her children…. The willingness and ability of a man to protect a woman and her children…. The willingness and ability of a man to engage in direct parenting activities…
La passività femminile nei rapporti sessuali – confermata da centinaia di studi –validerebbe il modello standard: in ambito sessuale la donna concede favori all’uomo…
… in his now classic work The Evolution of Human Sexuality, psychologist Donald Symons confidently proclaimed that “among all peoples sexual intercourse is understood to be a service or favor that females render to males.”… geneticist A. J. Bateman: natural selection encourages “an undiscriminating eagerness in the males and a discriminating passivity in the females.”…
La concezione darwiniana è di tipo calvinista: siamo fatti per produrre (eternare i nostri geni) non per essere felici…
… Robert Wright… “We are built to be effective animals, not happy ones… This perspective on life incorporates the Protestant work ethic… old testament… ife must be endured, not enjoyed… Ethologist/primatologist Frans de Waal, one of the more open-minded philosophers of human nature, calls this Calvinist sociobiology…
Gli ovuli sono più rari dello sperma, il che scatena guerra tra gli uomini e segregazione delle donne… 
… “Women’s reproductive resources are precious and finite, and ancestral women did not squander them on just any random man,” writes evolutionary psychologist David Buss. “Obviously, women don’t consciously think that sperm are cheap and eggs are expensive,” Buss continues, “but women in the past who failed to exercise acumen before consenting to sex were left in the evolutionary dust; our ancestral mothers used emotional wisdom to screen out losers.”…
E istituisce anche il matrimonio come forma di convivenza privilegiata…
…  theorists believe that Homo sapiens is uniquely high in male parental investment (MPI) among primates. They argue that our high level of MPI forms the basis for the supposed universality of marriage… Wright: “In every human culture in the anthropological record, marriage…is the norm, and the family is the atom of social organization. Fathers everywhere feel love for their children…. This love leads fathers to help feed and defend their children, and teach them useful things.”…
La certezza della paternità è un bene prezioso e la segregazione della donna una conseguenza necessaria…
… Biologist Tim Birkhead agrees, writing, “The issue of paternity is at the core of much of men’s behaviour—and for good evolutionary reasons. In our primeval past, men who invested in children which were not their own would, on average, have left fewer descendents than those who reared only their own genetic offspring…
La teoria tradizionale si fonda però su assunti labili… innanzitutto la mancanza di condivisione e generosità anche in assenza di scorte cumulabili…
… A hunter could refuse to share his catch with other hungry people living in the close-knit band of foragers (including nieces, nephews, and children of lifelong friends) without being shamed, shunned, and banished from the community…
Ma anche le donne competono tra loro per assicurarsi la protezione dei più forti.
Questo doppio conflitto dà origine alla strategia mista. La donna sposa il ricco e lo tradisce con il bello e prestante…
…Conventional theory suggests she’ll marry a nice, rich, predictable, sincere guy likely to pay the mortgage, change the diapers, and take out the trash—but then cheat on him with wild, sexy, dangerous dudes, especially around the time she’s ovulating, so she’s more likely to have lover-boy’s baby. Known as the mixed strategy…
David Buss e i suoi colleghi hanno messo coerentemente in luce come da un simile modello emerga il sentimento della gelosia…
… Their hypothesis holds that if males and females have conflicting agendas concerning mating behavior, the differences should appear in the ways males and females experience sexual jealousy…. These researchers found that women were consistently more upset by thoughts of their mates’ emotional infidelity, while men showed more anxiety concerning their mates’ sexual infidelity, as the hypothesis predicts… According to the standard model, the worst-case scenario for a prehistoric woman in this evolutionary game would be to lose access to her man’s resources and support…  From the man’s perspective, as noted above, the worst-case scenario would be to spend his time and resources raising another man’s children…
Anche all’uomo conviene sposarsi e poi tradire
… The male’s mixed strategy would be to have a long-term mate, whose sexual behavior he could control… Meanwhile he should continue having casual (low-investment) sex with as many other women as possible, to increase his chances of fathering more children… The woman’s mixed strategy would be to extract a long-term commitment from the man who offers her the best access to resources, status, and protection, while still seeking the occasional fling with rugged dudes in leather jackets who offer genetic advantages her loving, but domesticated, mate lacks…
Il modello standard vuole il maschio uno sporco bugiardo e bastardo.
La doppia strategia mista genera la cosiddetta guerra tra i sessi alla base della quale sta il tentativo di sfruttamento reciproco.
Un altro elemento fondamentale della sessualità umana è l’ovulazione nascosta delle donne. A che serve? Prima di rispondere diciamo anche che la donna ha una ricettività estesa (ovvero una propensione al rapporto estesa lungo quasi l’intero ciclo). Il che solleva un dubbio…
… If we accept the assumption that women are not particularly interested in sex, other than as a way to manipulate men into sharing resources, why would human females have evolved this unusually abundant sexual capacity? Why not reserve sex for those few days in the cycle when pregnancy is most probable, as does practically every other mammal?…
Helen Fischer tenta di coniugare tutti questi elementi nella teoria standard: si tratterebbe di elementi che rafforzano il legame di coppia…
… What anthropologist Helen Fisher has called “the classic explanation” goes like this: both concealed ovulation and extended (or, more accurately, constant) sexual receptivity evolved among early human females as a way of developing and cementing the pair bond by holding the attention of a constantly horny male mate… because she was always available for sex, even when not ovulating, there was no reason for him to seek other females for sexual pleasure… because her fertility was hidden, he would be motivated to stick around all the time to maximize his own probability of impregnating her and to ensure that no other males mated with her at any time… “Silent ovulation kept a special friend in constant close proximity, providing protection and food the female prized.”18 Known as “mate guarding behavior” to scientists, contemporary women might call it “that insecure pest who never leaves me alone.”…
Ma ci sono teorie alternative: si tratterebbe di strumenti per confondere il maschio e salvare la prole “adulterina”… 
… Anthropologist Sarah Blaffer Hrdy offers a different explanation for the unusual sexual capacity of the human female. She suggests that concealed ovulation and extended receptivity in early hominids may have evolved not to reassure males, but to confuse them. Having noted the tendency of newly enthroned alpha male baboons to kill all the babies of the previous patriarch, Hrdy hypothesized that this aspect of female sexuality may have developed as a way of confusing paternity among various males. The female would have sex with several males so that none of them could be certain of paternity, thus reducing the likelihood that the next alpha male would kill offspring who could be his…
La teoria standard lascia dubbiosi molti ricercatori. A questi dubbi si aggiungono quelli generati dallo studio delle scimmie antropomorfe: praticamente nessuna tra loro è monogamica…
… Genetically, the chimps and bonobos at the zoo are far closer to you and the other paying customers than they are to the gorillas, orangutans, monkeys, or anything else in a cage. Our DNA differs from that of chimps and bonobos by roughly 1.6 percent, making us closer to them than a dog is to a fox, a white-handed gibbon to a white-cheeked crested gibbon, an Indian elephant to an African elephant or, for any bird-watchers who may be tuning in, a red-eyed vireo to a white-eyed vireo… The ancestral line leading to chimps and bonobos splits off from that leading to humans just five to six million years ago…  with the chimp and bonobo lines separating somewhere between 3 million and 860,000 years ago… gorilla peeled away from the common line around nine million years ago, orangutans 16 million, and gibbons, the only monogamous ape, took an early exit about 22 million years ago…
Con un’immagine geografica
… Homo sapiens sapiens: New York, New York. Chimps and bonobos are practically neighbors, living within thirty miles of each other in Bridgeport, Connecticut, and Yorktown Heights, New York. Both just fifty miles from New York, they are well within commuting distance of humanity. Gorillas are enjoying cheese-steaks in Philadelphia, Pennsylvania. Orangutans are in Baltimore, Maryland, doing whatever it is people do in Baltimore. Gibbons are busily legislating monogamy in Washington, D.C. Old-world monkeys (baboons, macaques) are down around Roanoke, Virginia…
I bonobo, pur essendo le scimmie più simili a noi, hanno una sessualità che non si adatta di certo al modello standard sopra tratteggiato…
…For bonobos, a turbocharged sexuality utterly divorced from reproduction is a central feature of social interaction and group cohesion… The payoff is “a more intense form of social cooperation between males and females” leading to “a more intensely cooperative social group, a more secure milieu for rearing infants, and hence a higher degree of reproductive success for sexier males and females.”3 The bonobo’s promiscuity, in other words, confers significant evolutionary benefits on the apes…
L’unica scimmia monogama è il gibbone: una scimmia molto lontana da noi…
… The only monogamous ape, the gibbon, lives in Southeast Asia in small family units consisting of a male/female couple and their young—isolated in a territory of thirty to fifty square kilometers… Monogamy is not found in any social, group-living primate except—if the standard narrative is to be believed…
Per contro, la natura hobbesiana dello scimpanzé – l’altro nostro parente più prossimo – è indiscutibile…
… If Thomas Hobbes had been offered the opportunity to design an animal that embodied his darkest convictions about human nature, he might have come up with something like a chimpanzee… Chimps are reported to be power-mad, jealous, quick to violence, devious, and aggressive. Murder, organized warfare between groups, rape, and infanticide are prominent in accounts of their behavior… dale Peterson: Chimpanzee-like violence preceded and paved the way for human war, making modern humans the dazed survivors of a continuous, 5-million-year habit of lethal aggression.”…
Il parallelo con  i babbuini – un tempo in voga – oggi è decaduto…
… The baboon model was abandoned when it became clear that they lack some fundamental human characteristics: cooperative hunting, tool use, organized warfare, and power struggles involving complex coalition-building. Meanwhile, Jane Goodall and others were observing these qualities in chimpanzee behavior. Neuroscientist Robert Sapolsky—an expert on baboon behavior—notes that “chimps are what baboons would love to be like if they had a shred of self-discipline.”…
Vediamo l’organizzazione sociale dei bonobo:
… Bonobo Egalitarian and peaceful, bonobo communities are maintained primarily through social bonding between females, although females bond with males as well. Male status derives from the mother. Bonds between son and mother are lifelong. Multimale-multifemale mating…
Quella degli scimpanzé
… Chimpanzee The bonds between males are strongest and lead to constantly shifting male coalitions. Females move through overlapping ranges within territory patrolled by males, but don’t form strong bonds with other females or any particular male. Multimale-multifemale mating…
Uomini:
… Human By far the most diverse social species among the primates, there is plentiful evidence of all types of socio-sexual bonding, cooperation, and competition among contemporary humans. Multimale-multifemale mating…
Gorilla:
… Gorilla Generally, a single dominant male (the so-called “Silverback”) occupies a range for his family unit composed of several females and young. Adolescent males are forced out of the group as they reach sexual maturity. Strongest social bonds are between the male and adult females. Polygynous mating…
Oranghi:
… Orangutan Orangutans are solitary and show little bonding of any kind. Male orangutans do not tolerate each other’s presence. An adult male establishes a large territory where several females live. Each has her own range. Mating is dispersed, infrequent and often violent…
Gibboni:
… Gibbon Gibbons establish nuclear family units; each couple maintains a territory from which other pairs are excluded. Mating is monogamous…
C’è poi il dubbio che gli scimpanzé siano così truci…
… While chimps are extremely hierarchical, groups of human foragers are vehemently egalitarian. Meat sharing is precisely the occasion when chimp hierarchy is most evident, yet a successful hunt triggers the leveling mechanisms most important to human foraging societies… while data from the chimps studied by Goodall and others at Gombe appear to support the idea that a ruthless and calculating selfishness is typical of chimpanzee behavior, information from other study sites may contradict or undermine this finding…
L’alterazione degli ambienti dove gli scimpanzé sono osservati puo’ aver giocato un ruolo sostanziale nei comportamenti.
… There are also questions concerning how violent chimps are if left undisturbed in their natural habitat. As we discuss  later several factors could have profoundly altered the chimps’ observed behavior… Morris Breman: There are also questions concerning how violent chimps are if left undisturbed in their natural habitat. As we discuss in Chapter 13, several factors could have profoundly altered the chimps’ observed behavior…
Studiosi come Richard Dawkins sono certi della nostra natura egoista, e quindi più vicina agli scimpanzé…
… “Be warned that if you wish, as I do, to build a society in which individuals cooperate generously and unselfishly towards a common good, you can expect little help from biological nature. Let us try to teach generosity and altruism, because we are born selfish.”…
Tuttavia, qui potrebbe prodursi un equivoco importante: dopo la rivoluzione agricola ha senso pensare ad un comportamento notevolmente diverso poiché le scorte generano ricchezza e quindi egoismo. Ma prima della rivoluzione agricola non c’erano scorte e nemmeno penuria di risorse: la nostra matura si è evoluto in un ambiente ben diverso da quello attuale…
Human groups tend to respond to food surplus and storage with behavior like that observed in chimps: heightened hierarchical social organization, intergroup violence, territorial perimeter defense, and Machiavellian alliances. In other words, humans—like chimps—tend to fight when there’s something worth fighting over. But for most of prehistory, there was no food surplus to win or lose and no home base to defend….
De Waal riassume bene il diverso approccio di bonobo e scimpanzé ai problemi quotidiani
… “the chimpanzee resolves sexual issues with power; the bonobo resolves power issues with sex.”… “In war as in romance, bonobos and chimpanzees appear to be strikingly different. When two bonobo communities meet at a range boundary at Wamba…not only is there no lethal aggression as sometimes occurs in chimps, there may be socializing and even sex between females and the enemy community’s males.”… Just imagine that we had never heard of chimpanzees or baboons and had known bonobos first. We would at present most likely believe that early hominids lived in female-centered societies, in which sex served important social functions and in which warfare was rare or absent…. Bonobos have no formalized rituals of dominance and submission like the status displays common to chimps, gorillas, and other primates. Although status is not completely absent, primatologist Takayoshi Kano, who has collected the most detailed information on bonobo behavior in the wild, prefers to use the term “influential” rather than “high-ranking” when describing female bonobos…
Il matriarcato dei bonobo ci consente di approfondire questa istituzione: il dominio delle femmine non richiede alcuna sottomissione e in un matriarcato i maschi se la spassano alla grande…
… Those looking for evidence of matriarchy in human societies might ponder the fact that among bonobos, female “dominance” doesn’t result in the sort of male submission one might expect if it were simply an inversion of the male power structures found among chimps and baboons. The female bonobos use their power differently than male primates… Despite their submissive social role, male bonobos appear to be much better off than male chimps or baboons. As we’ll see in later discussions of female-dominated societies, human males also tend to fare pretty well when the women are in charge. While Sapolsky chose to study baboons because of the chronically high stress levels males suffer as a result of their unending struggles for power, de Waal notes that bonobos confront a different sort of existence, saying, “in view of their frequent sexual activity and low aggression, I find it hard to imagine that males of the species have a particularly stressful time.”…
A questo punto si pone la domanda cruciale: perchè per decifrare il nostro passato e quindi la nostra natura prendiamo ad esempio gli scimpanzè e non i bonobo? Dal punto di vista genetico le due scimmie sono equidistanti da noi e dal punto di vista dell’organizzazione sociale i bonobo sono forse più simili a come eravamo noi. Anche il parto ci avvicina ai bonobo…
… female bonobos resume sexual behavior within a year of parturition.” Both these otherwise unique qualities of bonobo sexuality are shared by only one other primate species: Homo sapiens…
Molti studiosi sono affetti da “flinstonizzazione”? Che significa:
… By projecting recent post-agricultural preoccupations with female fidelity into their vision of prehistory, many theorists have Flint-stonized their way right into a cul-de-sac…
D’altronde de Wall segnala l’assenza di un warfare presso l’uomo primitivo, e anche la natura egalitaria della sua organizzazione sociale… 
… he acknowledges and explains the virtual absence of organized warfare among today’s human foragers, their egalitarian tendencies, and generosity with information and resources across groups….
Se dovessimo far prevalere il modello bonobo per spiegare la vita sessuale dell’uomo primitivo, dovremmo concludere che la gelosia è un portato culturale più che genetico:
… Modern man’s seemingly instinctive impulse to control women’s sexuality is not an intrinsic feature of human nature. It is a response to specific historical socioeconomic conditions—conditions very different from those in which our species evolved. This is key to understanding sexuality in the modern world. De Waal is correct that this hierarchical, aggressive, and territorial behavior is of recent origin for our species. It is, as we’ll see, an adaptation to the social world that arose with agriculture…
Chiudiamo con una sinossi che mette in luce come nella sfera strettamente sessuale l’abbinamento uomo/bonobo sia più calzante di quello uomo/scimpanzé…
… Human and bonobo females copulate throughout menstrual cycle, as well as during lactation and pregnancy. Female chimps are sexually active only 25–40 percent of their cycle.
Human and bonobo infants develop much more slowly than chimpanzees, beginning to play with others at about 1.5 years, much later than chimps.
Like humans, female bonobos return to the group immediately after giving birth and copulate within months. They exhibit little fear of infanticide, which has never been observed in bonobos—captive or free-living.
Bonobos and humans enjoy many different copulatory positions, with ventral-ventral (missionary position) appearing to be preferred by bonobo females and rear-entry by males, while chimps prefer rear-entry almost exclusively.
Bonobos and humans often gaze into each other’s eyes when copulating and kiss each other deeply. Chimps do neither.
The vulva is located between the legs and oriented toward the front of the body in humans and bonobos, rather than oriented toward the rear as in chimps and other primates.
Food sharing is highly associated with sexual activity in humans and bonobos, only moderately so in chimps.
There is a high degree of variability in potential sexual combinations in humans and bonobos; homosexual activity is common in both, but rare in chimps.
Genital-genital (G-G) rubbing between female bonobos appears to affirm female bonding, is present in all bonobo populations studied (wild and captive), and is completely absent in chimpanzees. Human data on G-G rubbing are presently unavailable. (Attention: ambitious graduate students!)
While sexual activity in chimps and other primates appears to be primarily reproductive, bonobos and humans utilize sexuality for social purposes (tension reduction, bonding, conflict resolution, entertainment, etc.)…
COMMENTO PERSONALE
Trovo la riforma proposta valide e sostenuta da argomenti solidi: laddove le risorse sono poche, facilmente reperibili e non immagazzinabili (il caso estremo è la raccolta della frutta) si forma una sorta di egalitarismo. Dove c’è egalitarismo l’esclusività del partner ha poco senso, il che rende coerente una maggiore promiscuità sessuale.