There is no robust evidence of nonhuman suicides, notwithstanding countless opportunities for such self-killings, if they occurred, to be documented by the world’s farmers, animal breeders, naturalists, and scientists. We are left with anecdote and fable, including the scorpion’s self-sting, proffered by Peña-Guzmán as an example of animal suicide despite clear evidence that scorpions cannot sting themselves to death.

Scorpions are immune to their own venom, presumably because selection has eliminated the germ lines of scorpions that were not so protected. The ubiquity of such specific, self-preserving adaptations connects to a third, theoretical, problem with animal suicide: the absence of a coherent explanation as to how selection could favour and maintain such a capability. […]

Suicide is not observed in nonhumans for a straightforward evolutionary reason: any genes that permitted suicide would have been eliminated along with the suicides’ bodies. Any animal that, in the absence of restraints, was capable of escaping its pain and suffering by self- killing would be expected to seize the opportunity, because some pain is unavoidable in the Malthusian theatre in which selection plays out, and because pain is designed to motivate action to escape. A suicidal animal, if it appeared, would face a predictable and severe adaptive problem – the kind of problem that selection would expectably and powerfully have addressed in the evolutionary past.

The most parsimonious explanation for the apparent absence of suicide among younger children, the severely cognitively impaired, and nonhuman animals, is that these populations lack the cognitive wherewithal to conceive and enact it.

{ Animal Sentience | PDF }

acrylic on canvas { Olivier Mosset, Untitled, 1970 }

I know the boy will well usurp the grace, Voice, gait and action of a gentlewoman


This study documents that men and women experience and perform consumer shopping differently. […]

There is an abundant literature on sex differences in spatial abilities and object location that follow from the specific navigational strategies associated with hunting and gathering in the ancestral environment. In addition to sex differences in navigational strategies, the unique features of hunting and gathering may have influenced other aspects of foraging psychology that underlie sex differences in modern male and female shopping experiences and behaviors. […]

It is well accepted that humans do not simply develop new behaviors for every new situation we encounter but instead modify or extend existing behaviors to suit the new situation. Thus, the behaviors we exhibit in a modern and recently developed (i.e., with respect to an evolutionary timeframe) shopping mall, should be based on previously developed behaviors and skills. We believe, and study findings support this belief, that modern shopping behaviors are an adaptation of our species’ ancestral hunting and gathering skills. […]

For the most part, contemporary stereotypes of women in modern industrial countries perceive women as enjoying shopping more than men. Our research provides evidence that this popular stereotype exists because most shopping activities have a greater similarity to women’s traditional activities of foraging and gathering than they do to men’s traditional activity of hunting. The results of our study show that shopping has significantly more in common with gathering than it does with hunting.

{ Journal of Social, Evolutionary, and Cultural Psychology | Continue reading }

related { Hunter-gatherer lifestyle could help explain superior ability to ID smells }

if it moves fuck it


In a mossy forest in the western Andes of Ecuador, a small, cocoa-brown bird with a red crown sings from a slim perch. […] Three rival birds call back in rapid response. […] They are singing with their wings, and their potential mates seem to find the sound very alluring. […]

This is an evolutionary innovation — a whole new way to sing. But the evolutionary mechanism behind this novelty is not adaptation by natural selection, in which only those who survive pass on their genes, allowing the species to become better adapted to its environment over time. Rather, it is sexual selection by mate choice, in which individuals pass on their genes only if they’re chosen as mates. From the peacock’s tail to the haunting melodies of the wood thrush, mate choice is responsible for much of the beauty in the natural world.

Most biologists believe that these mechanisms always work in concert — that sex appeal is the sign of an objectively better mate, one with better genes or in better condition. But the wing songs of the club-winged manakin provide new insights that contradict this conventional wisdom. Instead of ensuring that organisms are on an inexorable path to self-improvement, mate choice can drive a species into what I call maladaptive decadence — a decline in survival and fecundity of the entire species. It may even lead to extinction.

{ NYT | Continue reading }

art { Cy Twombly, Achilles Mourning the Death of Patroclus, 1962 }

People are afraid to merge on freeways in Los Angeles


Most people in industrialized societies grow up in core (parents only) families with few if any siblings. Based on an evolutionary perspective, it may be argued that this environment reflects a mismatch, in that the tribal setting offered a larger number of close affiliates. The present project examined whether this mismatch may have a negative impact on mental health. […]

The number of household members correlated with scores on good mental health at all ages tested (3, 5 and 8 years). […] Living with a single mother did not make any difference compared to two parents. Girls were slightly more responsive to the presence of siblings than boys. Household pets did not have any appreciable impact.

{ BMC Psychology | Continue reading }

You’re stuck in the middle, and the pain is thunder


The classic argument is that those of our ancestors who saw more accurately had a competitive advantage over those who saw less accurately and thus were more likely to pass on their genes that coded for those more accurate perceptions, so after thousands of generations we can be quite confident that we’re the offspring of those who saw accurately, and so we see accurately. That sounds very plausible. But I think it is utterly false. It misunderstands the fundamental fact about evolution, which is that it’s about fitness functions — mathematical functions that describe how well a given strategy achieves the goals of survival and reproduction. […]

Evolution has shaped us with perceptions that allow us to survive. But part of that involves hiding from us the stuff we don’t need to know. And that’s pretty much all of reality, whatever reality might be.

{ Quanta | Continue reading }

cloaked in the pall of the ace of spaces


Venturing into novel terrain poses physical risks to a female and her offspring. Females have a greater tendency to avoid physical harm, while males tend to have larger range sizes and often outperform females in navigation-related tasks. Given this backdrop, we expected that females would explore a novel environment with more caution than males, and that more-cautious exploration would negatively affect navigation performance. […]

Findings support the idea that the fitness costs associated with long-distance travel may encourage females to take a more cautious approach to spatial exploration, and that this caution may partially explain the sex differences in navigation performance.

{ Human Nature | Continue reading }

When you knew that it was over were you suddenly aware that the autumn leaves were turning to the color of her hair?


In Women After All: Sex, Evolution, and the End of Male Supremacy, Melvin Konner argues that male domination is an anomaly of human history, not a natural state for the human species. Specifically, Konner suggests that male supremacy is largely an effect of an oppressive social arrangement, namely civilization, which began with the invention of agriculture when humans began to form permanent settlements. Permanent settlements enabled men to be able to accumulate resources and allowed population densities to increase mainly through higher birth rates. Higher population densities placed more intense pressure on the land’s resources. Therefore, it became necessary for men to form coalitions with neighbors to defend against intruders. Power became concentrated in the hands of a few men, leading to a stratified society where male supremacy and female subordination reigned and male violence and war intensified. Today, Konner argues that technology limits the need for the muscle and strength of men, and male domination has outlived its purpose and is maladaptive. Therefore, empowering women is the next step in human evolution. Through empowering women, equality between the sexes will be restored and man-made disasters, such as wars, sex scandals, and financial corruption, will significantly decrease or be eliminated since women (who Konner claims are less emotional than men) will be in positions of leadership and power.

{ Evolutionary Psychology | Continue reading }

Towards a Fictionalist Philosophy of Mathematics


We now have four good Darwinian reasons for individuals to be altruistic, generous or ‘moral’ towards each other. First, there is the special case of genetic kinship. Second, there is reciprocation: the repayment of favours given, and the giving of favours in ‘anticipation’ of payback. Following on from this there is, third, the Darwinian benefit of acquiring a reputation for generosity and kindness. And fourth, if Zahavi is right, there is the particular additional benefit of conspicuous generosity as a way of buying unfakeably authentic advertising.

{ Richard Dawkins | Continue reading }

photo { Todd Fisher }

‘Il y a dans la jalousie plus d’amour-propre que d’amour.’ –La Rochefoucauld


A recent Norwegian study shows that men and women react differently to various types of infidelity. Whereas men are most jealous of sexual infidelity, so-called emotional infidelity is what makes women the most jealous. Evolutionary psychology may help explain why this may be. […]

Men and women over thousands of generations have had to adapt to different challenges that are related to reproduction. Infidelity is one such challenge. A man must decide whether he really is the father of his partner’s child, and if he should choose to invest all his protection and status resources on this child. Since the dawn of time men have grappled with paternity insecurity, since fertilization occurs inside a woman’s body.

According to the evolutionary psychology explanation, men’s jealousy is an emotional reaction to signs of sexual infidelity. The jealousy serves to reduce the chances that his partner is cheating, since he then monitors her more closely.

It’s a different story for the child’s mother. She knows for sure that she is the child’s mother, but she must ensure that the child’s father will provide their offspring with food and the security and social status it needs. The greatest threat for the woman is not that the man has sex with other women, but that he spends time and resources on women other than her.

{ Medical Xpress | Continue reading }

(A firm heelclacking is heard on the stairs.)


The ratio between the body circumference at the waist and the hips (or WHR) is a secondary sexual trait that is unique to humans and is well known to influence men’s mate preferences. Because a woman’s WHR also provides information about her age, health and fertility, men’s preference concerning this physical feature may possibly be a cognitive adaptation selected in the human lineage. […]

We analyzed the WHR of women considered as ideally beautiful who were depicted in western artworks from 500 BCE to the present. These vestiges of the past feminine ideal were then compared to more recent symbols of beauty: Playboy models and winners of several Miss pageants from 1920 to 2014. We found that the ideal WHR has changed over time in western societies: it was constant during almost a millennium in antiquity (from 500 BCE to 400 CE) and has decreased from the 15th century to the present. Then, based on Playboy models and Miss pageants winners, this decrease appears to slow down or even reverse during the second half of the 20th century.

The universality of an ideal WHR is thus challenged, and historical changes in western societies could have caused these variations in men’s preferences.

{ PLOS | Continue reading }

You live and you learn


The “hygiene hypothesis” […] suggests that people in developed countries are growing up way too clean because of a variety of trends, including the use of hand sanitizers and detergents, and spending too little time around animals.

As a result, children don’t tend to be exposed to as many bacteria and other microorganisms, and maybe that deprives their immune system of the chance to be trained to recognize microbial friend from foe.

That may make the immune system more likely to misfire and overreact in a way that leads to allergies, eczema and asthma, Hesselmar says. […]

In their latest research, the researchers took a look at how people wash their dishes. […] In families who said they mostly wash dishes by hand, significantly fewer children had eczema, and somewhat fewer had either asthma or hay fever, compared to kids from families who let machines wash their dishes.

{ NPR | Continue reading }

photo { Daria Zhemkova photographed by Mario Kroes }

Brass and reeds, brace and ready!


A study has shown that in contemporary hunter-gatherer tribes, men and women tend to have equal influence on where their groups lives and who they live with. The findings challenge the idea that sexual equality is a recent invention, suggesting that it has been the norm for humans for most of our evolutionary history.

Mark Dyble, an anthropologist who led the study at University College London, said: “There is still this wider perception that hunter-gatherers are more macho or male-dominated. We’d argue it was only with the emergence of agriculture, when people could start to accumulate resources, that inequality emerged.” […]

Dyble said that egalitarianism may even have been one of the important factors that distinguished our ancestors from our primate cousins. “Chimpanzees live in quite aggressive, male-dominated societies with clear hierarchies,” he said. “As a result, they just don’t see enough adults in their lifetime for technologies to be sustained.”

{ Raw Story | Continue reading }