The present studies investigated the relationships between men’s perceived risk of experiencing sperm competition (i.e., when the ejaculates of two or more men simultaneously occupy the reproductive tract of a single woman), and their use of strategies to detect, prevent, and correct their partner’s sexual infidelity.

We investigated these associations using self-reports provided by men (Study 1, n = 113), partner-reports provided by women (Study 2, n = 136), and dyadic reports (Study 3, n = 103 couples).

The results of these studies indicated that the attractiveness of women was consistently associated with men’s use of benefit-provisioning mate retention behaviors (e.g., buying expensive gifts for one’s partner, showing signs of physical affection) and semen-displacing behaviors (e.g., deeper copulatory thrusting, more thrusts during copulation), whereas the infidelity risk of women was often associated with men’s use of cost-inflicting mate retention behaviors (e.g., threatening to end the relationship, monopolization of partner’s free time).

{ Evolutionary Psychology | Continue reading }

Previous work provides evidence of adaptations to sperm competition in men. For example, men’s testes size relative to body weight is larger than for the monandrous gorilla, which experiences very low sperm competition risk. However, men’s relative testes size is smaller than that of chimpanzees, whose polygynandrous mating system generates substantial sperm competition. […]

Several studies provide evidence that men unconsciously increase sperm number in an ejaculate when they are at greater sperm competition risk. Specifically, men who spent a greater proportion of time apart from their partners since the couple’s last copulation (time during which a man cannot account for his partner’s sexual behavior) produce more sperm in their next in-pair copulatory ejaculate. […]

Researchers have also theorized that the morphology of the human penis suggests an evolved function as a semen displacement device. […]

Both sexes reported that men thrust more deeply and more quickly at the couple’s next copulation when they experienced contexts in which sperm competition is more likely to occur. […] Goetz and colleagues also found that as sperm competition risk increased, men performed more copulatory behaviors that might act to displace the sperm of a potential rival that may be present (such as more thrusts and deeper thrusts during copulation). […]

Symons (1979) argued that women’s orgasm and associated physiological structures such as the clitoris are byproducts of selection on male genitalia and orgasm. […] Research also indicates that orgasm increases the retention of sperm. […] ancestral men who were particularly interested in the occurrence of their partner’s copulatory orgasm may have been more successful in the context of sperm competition.

{ Personality and Individual Differences (2010) | Continue reading }

The infidelity-detection hypothesis for oral sex proposes that men perform oral sex to gather information about their partner’s recent sexual history. […] men at a greater recurrent risk of sperm competition expressed greater interest in, and spent more time performing, oral sex on their partner

{ Personality and Individual Differences (2012) | Continue reading | More: Is Cunnilingus-Assisted Orgasm a Male Sperm-Retention Strategy? }

{ In contrast to an epiphany, an apophany does not provide insight into the nature of reality nor its interconnectedness | Images acquired over 3 Mars years showing heart-shaped features found on Mars | NASA }

[T]he reason someone may live beyond 100 years starts with their DNA […] “You can’t make it out that far without having already won the genetic lottery at birth” […] The longer your parents live, the more likely you’ll live a healthier, longer life, experts say. […]

“It’s probably not one single gene but a profile, a combination of genes”

Nir Barzilai, the director of the Institute for Aging Research at the Albert Einstein College of Medicine in the Bronx, has studied the lives of hundreds of centenarians, the people they’ve married and their kids. The children of centenarians are “about 10 years healthier” than their peers, Barzilai said. […]

The plan is to use artificial intelligence to help find the genes and develop drugs from them

{ Washington Post | Continue reading }

Adult individuals frequently face difficulties in attracting and keeping mates, which is an important driver of singlehood.

In the current research, we investigated the mating performance (i.e., how well people do in attracting and retaining intimate partners) and singlehood status in 14 different countries, namely Austria, Brazil, China, Greece, Hungary, Italy, Japan, Peru, Poland, Russia, Spain, Turkey, the UK, and Ukraine (N = 7,181).

We found that poor mating performance was in high occurrence, with about one in four participants scoring low in this dimension, and more than 57% facing difficulties in starting and/or keeping a relationship.

Men and women did not differ in their mating performance scores, but there was a small yet significant effect of age, with older participants indicating higher mating performance.

{ Evolutionary Psychology | Continue reading }

design { Ken Kelleher }

The cells that make up our body are constantly making new cells by dividing. A biological technicality causes us to lose a bit of DNA at the ends of our chromosomes (structures made up of DNA and proteins) after each replication. DNA contains the blueprint for our lives, so in order to make sure we aren’t losing crucial information during these divisions, the long molecules of DNA are protected by shorter segments of DNA at their ends called “telomeres.” An analogy would be the plastic tips on a shoelace that prevent it from unraveling. When a cell multiplies, the only part of the chromosome that is lost is a piece of the telomeres. But as we age, our telomeres get shorter, until they reach a critical point where the cell can no longer replicate without damage to its essential DNA. When this occurs, the cell becomes inactive or dies. Shortening of telomeres is linked to senescence and increased risk of disease. Other contributors to aging include oxidative stress (hence the appeal of antioxidants).

Lobsters have a perpetual supply of telomerase – the enzyme that can restore telomeres, helping cells avoid that fateful end. Humans also have telomerase, just not enough to overcome the constant shortening of telomeres. In fact, telomerase is often found in cancer cells, giving tumours a survival advantage.

[A] large supply of telomerase can be a double-edged sword. Lobsters are still more likely to die with age because their hard-shell exoskeleton moults and has to be regrown. This requires reams of energy, eventually too much. As a result, common causes of death for lobsters are exhaustion, immobility, and shell disease, although the leading cause is still predation.

{ McGill | Continue reading }

Humans can think about possible states of the world without believing in them, an important capacity for high-level cognition.

Here we use fMRI and a novel “shell game” task to test two competing theories about the nature of belief and its neural basis.

According to the Cartesian theory, information is first understood, then assessed for veracity, and ultimately encoded as either believed or not believed. According to the Spinozan theory, comprehension entails belief by default, such that understanding without believing requires an additional process of “unbelieving”. […]

findings are consistent with a version of the Spinozan theory whereby unbelieving is an inhibitory control process.

{ PsyArXiv | Continue reading }

Elon Musk is going to launch a satellite that displays ads in space, reports @BusinessInsider.

He is one of several billionaires investing vast sums on the space race.

SpaceX will launch the satellite with a display screen in 2022.

Ad space will be bought using cryptocurrency.

{ AJPlus | More: Daily Mail }

Nimrod, the builder of cities from Babel to Calah, was the first “mighty man” on earth, and a “mighty hunter before the Lord.” So were other African, Asian, European, and New World kings. They hunted everything from lions to guanacos, on four of the six continents, from the beginning of recorded time. But why?

Hunting provided meat, and it may have also provided military exercises; but most kings subsisted on domesticated animals and plants and delegated their wars to specialists. […]

Hunting was extremely expensive. Kings lost time with their ministers and with their families; they spent enormous resources on elephants and horses, hounds, hawks, manpower, and fodder. In addition to the obvious time and money costs, there were huge risks. Hunting kings and their sons were often wounded. And more than a few died. […]

Some were felled by stray arrows, whereas others were felled by their own arrows; some caught cold in the forest, and others fell off their horses. It is impossible to quantify the time and money costs or the morbidity and mortality risks. However, a list of anecdotes is impressive: Plenty of kings were wounded or killed chasing game in the woods. […]

The benefits seem to have been outweighed by the costs. […]

Evolutionary psychology is predicated on the assumption that humans are collections of vestiges; that Pleistocene ecologies shaped our mental and physical traits, which are often at odds with modern environments, and maladaptive behaviors resulted. Hunting was the human adaptation on the savannah for hundreds of thousands of years. Good hunters won mates by providing meat; or they attracted them by showing off the talents involved in killing game. Human bodies and minds should have been shaped to reflect those facts.

{ Cross-Cultural Research | PDF }

image { Horse Laughs (1891) }

Eye Contact Marks The Rise And Fall of Shared Attention in Conversation

Conversation is the platform where minds meet —the venue where information is shared, ideas co-created, cultural norms shaped, and social bonds forged. Its frequency and ease belie its complexity.

Every conversation weaves a unique shared narrative from the contributions of independent minds, requiring partners to flexibly move into and out of alignment as needed for conversation to both cohere and evolve. How two minds achieve this coordination is poorly understood.

Here we test whether eye contact, a common feature of conversation, predicts this coordination by measuring dyadic pupillary synchrony (a corollary of shared attention) during natural conversation.

We find that eye contact is positively correlated with synchrony as well as ratings of engagement by conversation partners.

However, rather than elicit synchrony, eye contact commences as synchrony peaks and predicts its immediate and subsequent decline until eye contact breaks. This relationship suggests that eye contact signals when shared attention is high.

Further, we speculate that eye contact may play a corrective role in disrupting shared attention (reducing synchrony) as needed to facilitate independent contributions to conversation.

{ PsyArXiv | Continue reading }

photo { Edward Weston, Flora Chandler Weston, 1909 }

In building your book I wanted to pursue my own process of decomposition.  I began to think about the ways in which paper degrades.  Rotting in the ground, exposure to rain, chemicals (I used Xylene, a paint thinner, for the image transfers on the cover), and fire.  Although rain or burying paper in the ground would have created unique and unpredictable patterns of ruin in the paper, these seemed like passive processes, whereas burning paper could achieve some level of stochastic design but in a more involved, active, and risk-exposed situation.   I followed the traditional recipe for Chinese blackpowder: 75% potassium nitrate, or saltpeter, 15% carbon, 10% sulphur. […]

On a hot plate, outside, the potassium nitrate is usually dissolved in a pot of water, however instead of water I poured into the potassium nitrate a jar of my stale, sunbaked urine since it accelerates the burn process.  

{ Big Other | Continue reading }

{ Prosopometamorphopsia is an extremely rare disorder of visual perception characterised by facial distortions }

for every generation until now, climate change has always been “the next generation’s problem.”

{ Real Life | Continue reading }

Between the 1970s and the early aughts, the incidence of myopia in the US nearly doubled, to 42 percent. Myopia’s rise has been the starkest in Asia; one survey in Korea found a rate as high as 96 percent among teenagers.

Clearly, something is going on. But scientists can’t agree on exactly what. Being constantly tethered to devices and books indoors might be part of it: Based on a handful of large epidemiological studies on myopia, spending time outdoors—especially in early childhood—reduces the onset of myopia. […]

Neuroscientists discovered the classic animal model for myopia by accident in the 1970s, when they were sewing one eye shut in newborn monkeys to study the development of the brain’s visual system. […] Around the same time as the eye-sewing experiments, neuroscientists figured out they could do the same in chickens and tree shrews—much easier to keep in the lab than monkeys. And instead of sewing the eyelid shut, they could just put what looks like half a ping pong ball over the eye. This “form deprivation” model of myopia has inspired some fascinating science. In 2010, for example, Morgan’s collaborators found that exposure to bright light could reverse this type of induced myopia in chickens. Further experiments pinned down the mechanism, too: Light activates the neurotransmitter dopamine, which prevents the eyes from growing longer.

{ Wired | Continue reading }

NYC man sells fart for $85, cashing in on NFT craze […] Ramírez-Mallis and his fellow farters compiled the recordings into a 52-minute “Master Collection” audio file. Now, the top bid for the file is currently $183. Individual fart recordings are also available for 0.05 Ethereum, or about $85 a pop.

{ NY Post | Continue reading }

unrelated { Illegal Content and the Blockchain }

Back in the 1980s, when DNA forensic analysis was still in its infancy, crime labs needed a speck of bodily fluid—usually blood, semen, or spit—to generate a genetic profile.

That changed in 1997, when Australian forensic scientist Roland van Oorschot stunned the criminal justice world with a nine-paragraph paper titled “DNA Fingerprints from Fingerprints.” It revealed that DNA could be detected not just from bodily fluids but from traces left by a touch. Investigators across the globe began scouring crime scenes for anything—a doorknob, a countertop, a knife handle—that a perpetrator may have tainted with incriminating “touch” DNA.

But van Oorschot’s paper also contained a vital observation: Some people’s DNA appeared on things that they had never touched. […]

In one of his lab’s experiments, for instance, volunteers sat at a table and shared a jug of juice. After 20 minutes of chatting and sipping, swabs were deployed on their hands, the chairs, the table, the jug, and the juice glasses, then tested for genetic material. Although the volunteers never touched each other, 50 percent wound up with another’s DNA on their hand. A third of the glasses bore the DNA of volunteers who did not touch or drink from them.

Then there was the foreign DNA—profiles that didn’t match any of the juice drinkers. It turned up on about half of the chairs and glasses, and all over the participants’ hands and the table. The only explanation: The participants unwittingly brought with them alien genes, perhaps from the lover they kissed that morning, the stranger with whom they had shared a bus grip, or the barista who handed them an afternoon latte.

{ Wired | Continue reading }

related { The Hunt for the Golden State Killer and A New Way to Solve Murders }

Romantic love is a basic brain system, like fear and anger or disgust. We humans have evolved three distinct brain systems for mating and reproduction: the sex drive, romantic love, and feelings of deep attachment. People make the mistake of thinking that these are phases. They’re not phases, they’re brain systems, and they can operate in any combination and order. […]

I estimate the people I studied, on average, thought about their beloved about 85 percent of the time. […]

I looked at the demographics from the United Nations from 1947–2011 and across 80 cultures. People tend to divorce around the fourth year of marriage. […]

{ Helen Fisher / Sapiens | Continue reading }

still { Catherine Deneuve in Jacques Demy’s Les Parapluies de Cherbourg, 1963 }

When he was two years old, Ben stopped seeing out of his left eye. His mother took him to the doctor and soon discovered he had retinal cancer in both eyes. After chemotherapy and radiation failed, surgeons removed both his eyes. For Ben, vision was gone forever.

But by the time he was seven years old, he had devised a technique for decoding the world around him: he clicked with his mouth and listened for the returning echoes. This method enabled Ben to determine the locations of open doorways, people, parked cars, garbage cans, and so on. He was echolocating: bouncing his sound waves off objects in the environment and catching the reflections to build a mental model of his surroundings.

Echolocation may sound like an improbable feat for a human, but thousands of blind people have perfected this skill, just like Ben did. The phenomenon has been written about since at least the 1940s, when the word “echolocation” was first coined in a Science article titled “Echolocation by Blind Men, Bats, and Radar.” […]

Neuroscience used to think that different parts of the brain were predetermined to perform specific functions. But more recent discoveries have upended the old paradigm. One part of the brain may initially be assigned a specific task; for instance, the back of our brain is called the “visual cortex” because it usually handles sight. But that territory can be reassigned to a different task. There is nothing special about neurons in the visual cortex: they are simply neurons that happen to be involved in processing shapes or colors in people who have functioning eyes. But in the sightless, these same neurons can rewire themselves to process other types of information. […]

we refer to the brain’s plasticity as “livewiring” to spotlight how this vast system of 86 billion neurons and 0.2 quadrillion connections rewires itself every moment of your life. […]

In Ben’s case, his brain’s flexible wiring repurposed his visual cortex for processing sound. As a result, Ben had more neurons available to deal with auditory information, and this increased processing power allowed Ben to interpret soundwaves in shocking detail. Ben’s super-hearing demonstrates a more general rule: the more brain territory a particular sense has, the better it performs. […]

Recent decades have yielded several revelations about livewiring, but perhaps the biggest surprise is its rapidity. Brain circuits reorganize not only in the newly blind, but also in the sighted who have temporary blindness. In one study, sighted participants intensively learned how to read Braille. Half the participants were blindfolded throughout the experience. At the end of the five days, the participants who wore blindfolds could distinguish subtle differences between Braille characters much better than the participants who didn’t wear blindfolds. Even more remarkably, the blindfolded participants showed activation in visual brain regions in response to touch and sound. When activity in the visual cortex was temporarily disrupted, the Braille-reading advantage of the blindfolded participants went away. In other words, the blindfolded participants performed better on the touch- related task because their visual cortex had been recruited to help. After the blindfold was removed, the visual cortex returned to normal within a day, no longer responding to touch and sound.

But such changes don’t have to take five days; that just happened to be when the measurement took place. When blindfolded participants are continuously measured, touch-related activity shows up in the visual cortex in about an hour. […]

In the ceaseless competition for brain territory, the visual system has a unique problem: due to the planet’s rotation, all animals are cast into darkness for an average of 12 out of every 24 hours. (Of course, this refers to the vast majority of evolutionary time, not to our present electrified world.) Our ancestors effectively were unwitting participants in the blindfold experiment, every night of their entire lives.

So how did the visual cortex of our ancestors’ brains defend its territory, in the absence of input from the eyes?

We suggest that the brain preserves the territory of the visual cortex by keeping it active at night. In our “defensive activation theory,” dream sleep exists to keep neurons in the visual cortex active, thereby combating a takeover by the neighboring senses. […]

In humans, sleep is punctuated by rapid eye movement (REM) sleep every 90 minutes. This is when most dreaming occurs. (Although some forms of dreaming can occur during non-REM sleep, such dreams are abstract and lack the visual vividness of REM dreams.)

REM sleep is triggered by a specialized set of neurons that pump activity straight into the brain’s visual cortex, causing us to experience vision even though our eyes are closed.

{ Time | Continue reading }

image { Michael Mann, Manhunter, 1986 }

quote { Does the popular quote, “No artist tolerates reality,” belong to Nietzsche? }

Previous studies on aesthetic chills (i.e., psychogenic shivers) demonstrate their positive effects on stress, pleasure, and social cognition. We tested whether we could artificially enhance this emotion and its downstream effects by intervening on its somatic markers using wearable technology.

{ Scientific Reports | Continue reading }

{ as coastal homeowners face rising sea levels brought on by climate change, the state is increasingly approving sandbags and other structures that are speeding the loss of its beaches | ProPublica | full story }

Female 29 years of age, university student, from dysfunctional family. She began her suffering 11 years ago with personality dissociation, characterized by aversion to sacred objects and images, and psychomotor agitation with transient states of loss of consciousness with manifestations of spiritual possession that required psychiatric, and psychological treatment, and 5 exorcisms without improvement over a period of ten years. […]

With informed consent, a fMRI was accomplished before and in the beginning of a possession induced by exorcism performed by a Catholic priest. […] due to the involuntary motor activity and the patient’s loss of consciousness, it is not possible to perform the analysis completely in this case.

{ Trends in Medicine | Continue reading }

There were 16 people in total that participated in the project “Resting Stated-Tractography-fMRI in initial phase of spiritual possession.” 13 of them are health professionals: a surgeon, psychiatrist, psychologist, neurophysiologist, family medicine physician, neurosurgeon, 2 radiology technicians, a gynecologist, medical doctor, diagnostic radiology physician, exorcist and patient (Ex former medical student). The priest, mother and an aunt of the patient were not included. […]

8 out of 13 participants (61.53%) had accidents and sudden events that put their lives in danger […]

Eight days before the exorcism, the psychiatrist experienced malfunctioning of his computer […]

Seven days after the exorcism, the surgeon had a head trauma, chest trauma and multiple bruises in a forest accident with fall from a height of one meter; he also had a MVA (motor vehicle accident) 15 minutes before receiving the images of the patient’s tractografies […]

22 days after the exorcism the medical doctor presented sudden breakup of a ten years relationship with her boyfriend.

Eight days before and during the exorcism, the father of the patient (a family medicine physician) presented chest and back pain with a normal electrocardiogram; 37 days after the exorcism he is admitted to the Critical Care Unit “CCU” for massive acute myocardial infarction, with loss of myocardial function of 90%.

41 days after the exorcism, the gynecologist is involved in an offense she did not commit.

[…]

On the survey carried out, the 12 participants are much more afraid of organized crime in Mexico than of the devil.

{ Trends in Medicine | PDF }