The idea of two sexes is simplistic. Biologists now think there is a wider spectrum than that.

The presence or absence of a Y chromosome is what counts: with it, you are male, and without it, you are female. But doctors have long known that some people straddle the boundary — their sex chromosomes say one thing, but their gonads (ovaries or testes) or sexual anatomy say another. Parents of children with these kinds of conditions — known as intersex conditions, or differences or disorders of sex development (DSDs) — often face difficult decisions about whether to bring up their child as a boy or a girl. Some researchers now say that as many as 1 person in 100 has some form of DSD. […]

That the two sexes are physically different is obvious, but at the start of life, it is not. Five weeks into development, a human embryo has the potential to form both male and female anatomy. Next to the developing kidneys, two bulges known as the gonadal ridges emerge alongside two pairs of ducts, one of which can form the uterus and Fallopian tubes, and the other the male internal genital plumbing: the epididymes, vas deferentia and seminal vesicles. At six weeks, the gonad switches on the developmental pathway to become an ovary or a testis. If a testis develops, it secretes testosterone, which supports the development of the male ducts. It also makes other hormones that force the presumptive uterus and Fallopian tubes to shrink away. If the gonad becomes an ovary, it makes oestrogen, and the lack of testosterone causes the male plumbing to wither. The sex hormones also dictate the development of the external genitalia, and they come into play once more at puberty, triggering the development of secondary sexual characteristics such as breasts or facial hair. […]

For many years, scientists believed that female development was the default programme, and that male development was actively switched on by the presence of a particular gene on the Y chromosome. In 1990, researchers made headlines when they uncovered the identity of this gene, which they called SRY. Just by itself, this gene can switch the gonad from ovarian to testicular development. For example, XX individuals who carry a fragment of the Y chromosome that contains SRY develop as males.

{ Nature | Continue reading }

Dr. Yalom, I would like a consultation. I’ve read your novel “When Nietzsche Wept,” and wonder if you’d be willing to see a fellow writer with a writing block.

No doubt Paul sought to pique my interest with his email. […] Ten days later Paul arrived for his appointment. […]

“I was in philosophy at Princeton writing my doctorate on the incompatibility between Nietzsche’s ideas on determinism and his espousal of self-transformation. But I couldn’t finish. I kept getting distracted by such things as Nietzsche’s extraordinary correspondence, especially by his letters to his friends and fellow writers like Strindberg.

“Gradually I lost interest altogether in his philosophy and valued him more as an artist. I came to regard Nietzsche as a poet with the most powerful voice in history, a voice so majestic that it eclipsed his ideas, and soon there was nothing for me to do but to switch departments and do my doctorate in literature rather than philosophy.

“The years went by,” he continued, “my research progressed well, but I simply could not write. Finally I arrived at the position that it was only through art that an artist could be illuminated, and I abandoned the dissertation project entirely and decided instead to write a novel on Nietzsche. But the writing block was neither fooled nor deterred by my changing projects. It remained as powerful and unmovable as a granite mountain. And so it has continued until this very day.”

I was stunned. Paul was an old man now. He must have begun working on his dissertation well over a half-century ago. […]

“Tell me more,” I said. “Your family? The people in your life?”

“No siblings. Married twice. Divorced twice. Mercifully short marriages. No children, thank God.”

This is getting very odd, I thought. So talkative at first, Paul now seems intent on giving me as little information as possible. What’s going on?

{ NY Times | Continue reading }

A fragrant object lies before you—say, a flower, some stinky cheese, or a smelly sock. Molecules break off from the object, evaporating into the air and floating towards your face. A sniff pulls the molecules into your nostril, where they travel through your nasal cavity towards your olfactory neurons, which extend out through holes in your skull into the mucus layer of your nose. The molecules activate receptors studding the outside layer of individual neurons, which send a message to your brain that something smells.

Humans have around 350 types of receptors on 40 million neurons, which in combination allow us to distinguish more than a trillion different odors. Despite this incredible power of olfaction, the human sense of smell is often neglected, considered a holdover from our animal past or a source of unseemly sensations. It doesn’t help that odors are often literally beneath us; the evolutionary argument goes that when early humans started walking upright, our nose got farther away from the smells on the ground, decreasing the relative importance of olfaction for getting around. Evidence contradicting this story came from a 2006 study which recruited undergraduate students to get on all fours and track the scent of chocolate oil dripped on grass. They were remarkably good at it, showing that our “bad” sense of smell isn’t biologically determined—it’s just that we’re out of practice. […]

We know a lot about how a smell signal travels from an activated receptor on a neuron to the brain. This pathway has been worked out in painstaking detail, with cascades of cellular switches and neural action potentials that signal our brain. […] But how does a smelly molecule activate its receptor in the first place? There is still no satisfactory answer to this question despite nearly a century of research.

{ The New Inquiry | Continue reading }

photo { Juno Calypso, Disenchanted Simulation, 2013 }

The scientific study of heartbreak is extremely new, with nearly all articles on the matter appearing in the last 10-15 years. In fact, the notion that strong emotional stress can impact health was not widely accepted in academia until recently.

In the 1990’s, Japan started accruing cases of a disease called “takotsubo cardiomyopathy,” where patients’ hearts would actually become damaged and their ventricles would be misshapen (into that of a “takotsubo,” or octopus-catching pot – a very bad shape for a heart chamber). Curiously, these cases were not heart attacks, but instead were a form of heart failure brought on by a rush of stress hormones.

After 15 years, the syndrome was finally mentioned in a 2005 New England Journal of Medicine article, where it was renamed “Broken Heart Syndrome.” Among the causes of Broken Heart Syndrome are romantic rejection, divorce, or the death of a loved one, and the outcome can be as serious as death.

{ NeuWrite | Continue reading }

On February 14th, Kakumei-teki himote doumei (革命的非モテ同盟) — literally, “Revolutionary Alliance of Men That Woman Are Not Attracted To”– will gather in Shibuya, an area of Tokyo popular with young couples, to protest Valentine’s Day and its roots in what they call “romantic capitalist oppression.”

The group, known as Kakuhidou for short, was started in 2006, when its founder, Katsuhiro Furusawa, returned home one day after being dumped by his girlfriend and began reading the Communist Manifesto. He quickly came to the realization that being unpopular with girls is a class issue.

{ Spoon & Tamago | Continue reading }

Women tend to prefer men who make them laugh and men tend to prefer women who laugh at their jokes. However, it is unclear how robust this pattern is. Here we report a replication of one of the first studies (Bressler, Martin, and Balshine, 2006) to examine the sex differences in preferences for humor receptivity versus humor production. […]

We found that men viewed humor receptivity as a necessity and humor production as a luxury when they were asked to create an ideal long-term partner. For women, it was just the opposite.

{ Evolutionary Psychology | PDF }

We study the influence of reason and intuition on decision-making over time. […]

We find that intuition will outperform reason in the long run if individuals are sufficiently ambitious. Moreover, intuitive decisions are prevalent in the early and late stages of a learning process, whereas reason governs decisions in intermediate stages.

{ Managerial and Decision Economics | Continue reading }

Does morality depend on the time of the day? The study “The Morning Morality Effect: The Influence of Time of Day on Unethical Behavior” published in October of 2013 by Maryam Kouchaki and Isaac Smith suggested that people are more honest in the mornings, and that their ability to resist the temptation of lying and cheating wears off as the day progresses. […]

One question not addressed by Kouchaki and Smith was whether the propensity to become dishonest in the afternoons or evenings could be generalized to all subjects or whether the internal time in the subjects was also a factor.

All humans have an internal body clock — the circadian clock — which runs with a period of approximately 24 hours. The circadian clock controls a wide variety of physical and mental functions such as our body temperature, the release of hormones or our levels of alertness. The internal clock can vary between individuals, but external cues such as sunlight or the social constraints of our society force our internal clocks to be synchronized to a pre-defined external time which may be quite distinct from what our internal clock would choose if it were to “run free”. Free-running internal clocks of individuals can differ in terms of their period (for example 23.5 hours versus 24.4 hours) as well as the phases of when individuals would preferably engage in certain behaviors. […]

Some people like to go to bed early, wake up at 5 am or 6 am on their own even without an alarm clock and they experience peak levels of alertness and energy before noon. In contrast to such “larks”, there are “owls” among us who prefer to go to bed late at night, wake up at 11 am, experience their peak energy levels and alertness in the evening hours and like to stay up way past midnight. […]

The researchers Brian Gunia, Christopher Barnes and Sunita Sah therefore decided to replicate the Kouchaki and Smith study with one major modification: They not only assessed the propensity to cheat at different times of the day, they also measured the chronotypes of the study participants. Their recent paper “”The Morality of Larks and Owls: Unethical Behavior Depends on Chronotype as Well as Time of Day” confirms that Kouchaki and Smith findings that the time of the day influences honesty, but the observed effects differ among chronotypes. […]

[M]orning morality effect and the idea of “moral exhaustion” towards the end of the day cannot be generalized to all. In fact, evening people (”owls”) are more honest in the evenings. […]

Gunia and colleagues only included morning and evening people in their analysis and excluded the participants who reported an intermediate chronotype, i.e. not quite early morning “larks” and not true “owls”. This is a valid criticism because newer research on chronotypes has shown that there is a Gaussian distribution of chronotypes. Few of us are extreme larks or extreme owls, most of us lie on a continuum.

{ Fragments of Truth | Continue reading }

photo { Steven Meisel }

No Big Bang? Quantum equation predicts universe has no beginning

The widely accepted age of the universe, as estimated by general relativity, is 13.8 billion years. In the beginning, everything in existence is thought to have occupied a single infinitely dense point, or singularity. Only after this point began to expand in a “Big Bang” did the universe officially begin.

Although the Big Bang singularity arises directly and unavoidably from the mathematics of general relativity, some scientists see it as problematic because the math can explain only what happened immediately after—not at or before—the singularity.

{ Phys.org | Continue reading }

Hilbert managed to build a hotel with an infinite number of rooms, all of which are occupied.

Suppose a new guest arrives and wishes to be accommodated in the hotel. Because the hotel has an infinite number of, we can move any guest occupying any room n to room n+1 (the occupant of room 1 moves to room 2, room 2 to room 3, and so on), then fit the newcomer into room 1.

Now suppose an infinite number of new guests arrives: just move any occupant of room n to room 2n (room 1 to room 2, room 2 to room 4, room 3 to room 6, and so on), and all the odd-numbered rooms (which are countably infinite) will be free for the new guests.

{ Wikipedia | Continue reading }

“The goal of memory isn’t to keep the details. It’s to be able to generalize from what you know so that you are more confident in acting on it,” Davachi says.

You run away from the dog that looks like the one that bit you, rather than standing around questioning how accurate your recall is.

{ The New Yorker | Continue reading }

Individuals who report experiencing communication with deceased persons are traditionally called mediums. During a typical mediumship reading, a medium conveys messages from deceased persons to the living (i.e., sitters). There are two types of mediumship: mental and physical. In mental mediumship, communication with deceased persons is experienced “through interior vision or hearing, or through the spirits taking over and controlling their bodies or parts thereof, especially … the parts required for speech and writing.” During physical mediumship, the experienced communication “proceeds through paranormal physical events in the medium’s vicinity,” which have included reports of independent voices, rapping sounds on walls or tables, and movement of objects. […]

Recent research has also confirmed previous findings that mediumship is not associated with conventional dissociative experiences, pathology, dysfunction, psychosis, or over-active imaginations. Indeed, a large percentage of mediums have been found to be high functioning, socially accepted individuals within their communities. […]

Psychometric and brain electrophysiology data were collected from six individuals who had previously reported accurate information about deceased individuals under double-blind conditions. Each experimental participant performed two tasks with eyes closed.

In the first task, the participant was given only the first name of a deceased person and asked 25 questions. After each question, the participant was asked to silently perceive information relevant to the question for 20 s and then respond verbally. Responses were transcribed and then scored for accuracy by individuals who knew the deceased persons. Of the four mediums whose accuracy could be evaluated, three scored significantly above chance (p < 0.03). The correlation between accuracy and brain activity during the 20 s of silent mediumship communication was significant in frontal theta for one participant (p < 0.01).

In the second task, participants were asked to experience four mental states for 1 min each: (1) thinking about a known living person, (2) listening to a biography, (3) thinking about an imaginary person, and (4) interacting mentally with a known deceased person. Each mental state was repeated three times. Statistically significant differences at p < 0.01 after correction for multiple comparisons in electrocortical activity among the four conditions were obtained in all six participants, primarily in the gamma band (which might be due to muscular activity). These differences suggest that the impression of communicating with the deceased may be a distinct mental state distinct from ordinary thinking or imagination.

{ Frontiers in Psychology | PDF }

Few studies have investigated the role of sleep deprivation in the formation of false memories, despite overwhelming evidence that sleep deprivation impairs cognitive function. We examined the relationship between self-reported sleep duration and false memories and the effect of 24 hr of total sleep deprivation on susceptibility to false memories. We found that under certain conditions, sleep deprivation can increase the risk of developing false memories.

{ Neuroethics & Law | Continue reading }

acrylic on canvas { William Betts, Amber, 03/19/04, 20:05:12, 2008 }

A car accident, the loss of a loved one and financial trouble are just a few of the myriad stressors we may encounter in our lifetimes. Some of us take it in stride, while others go on to develop anxiety or depression. How well will we deal with the inevitable lows of life?

A clue to this answer, according to a new Duke University study, is found in an almond-shaped structure deep within our brains: the amygdala. By measuring activity of this area, which is crucial for detecting and responding to danger, researchers say they can tell who will become depressed or anxious in response to stressful life events, as far as four years down the road.

{ EurekAlert | Continue reading }

Who prefers anonymous self-expression online? […] Favoring anonymity was positively correlated with both grandiosity, a component of narcissism, and low self-esteem. In addition, users with stronger anonymity preference tended to be younger, highly trusting, having strong ties to online communities while having few offline friends.

{ Taylor & Francis Online | Continue reading }

Campion was an ophthalmologist […] He became a testosterone doctor. […] The initial session costs $5,000, and the monthly charges are over $1,000. Clients get their blood work done every three months, so that Campion can keep tabs on how their “hormonal balancing” is going. Most patients lock into a permanent testosterone regimen, as Campion has. “I will take testosterone for the rest of my life,” he says. […]

Testosterone can be manufactured cheaply in large quantities, and the risks seem manageable for most people. Users report increased energy, more muscle mass, decreased body fat, greater sex drive, and a general sense of well-being. In short, it’s one of the most transformative substances a human can take. […]

According to a study by University of Texas epidemiologist Jacques Baillargeon, nearly four percent of men in their 60s are taking testosterone. The number of men between 40 and 64 went up 77 percent from 2010 to 2013 to 1.5 million men.

{ Fusion | Continue reading }

art { Andy Warhol, Eight Elvises, 1963 | The current owner and location of the painting, which has not been seen publicly since the 1960s, are unknown }

Memory has to be ‘turned on’ in order to remember even the simplest details, a new study finds. When not expecting to be tested, people can forget information just one second after paying attention to it. But, when they expect to be tested, people’s recall is doubled or even tripled.

{ PsyBlog | Continue reading }

photo { Spot | NYT }

The idea that unconscious thought is sometimes more powerful than conscious thought is attractive, and echoes ideas popularized by books such as writer Malcolm Gladwell’s best-selling Blink.

But within the scientific community, ‘unconscious-thought advantage’ (UTA) has been controversial. Now Dutch psychologists have carried out the most rigorous study yet of UTA—and find no evidence for it. […] The report adds to broader concerns about the quality of psychology studies and to an ongoing controversy about the extent to which unconscious thought in general can influence behaviour.

{ Scientific American | Continue reading }

art { Bronzino, Portrait of Lucrezia Panciatichi, 1545 }

Sex in reptiles and fish is determined after conception, during embryogenesis, according to ambient environmental temperature. In contrast, in mammals and birds, sex is determined at conception.

In mammals, male births invariably occur slightly in excess […] with approximately 3% more males born than females. The reason for this discrepancy is uncertain as testicles produce equal numbers of X-bearing and Y-bearing spermatozoa. […]

We have shown that M/F varies in geographical space, exhibiting a latitude gradient, and that this gradient is different in Europe and North America, with more males born towards the south of Europe, compared with the North American continent where more males are born towards the north of the continent.

Other studies have also shown that M/F may vary with time. Several authors have shown that M/F has declined over the second half of the 20th century in various industrialised countries. These include Denmark, the United Kingdom, the Netherlands, Germany, Canada, the United States of America, and Finland. In contrast, M/F has been noted to have risen in Ireland over the same period. A non-significant rise in M/F has also been noted in Australia and Japan.

{ J Epidemiol Community Health | Continue reading }

A wide variety of factors have been shown to influence the male to female ratio at birth, which invariably displays a male excess. […] It will be shown that stress, including stress related to political events, influences this ratio.

{ Early Human Development | Continue reading }

related { Study: ”Woman on top” is the most dangerous sex position, responsible for half of all penile fractures }

In an earlier experimental study by Zillman and Bryant (1988) male and female students were exposed to pornography once a week for six weeks. Those who viewed pornography reported being less satisfied with their partner’s appearance and sexual behavior. They also found that men who consumed pornography were more dominating and less attentive toward their partners. Hence, there is some reason to anticipate that pornography consumption impairs relationship commitment.

Other research suggests that pornography may be beneficial to relationships in some ways, especially in sexual relations. Some evidence suggests that consuming pornography influences individuals’ positive attitude toward sexuality and serves as a safe platform through which to en- gage in sexual exploration. […]

Using a variety of methods, we demonstrated that pornography consumption is associated with weakened commitment to one’s relationship partner. […] in Study 5 we examined a more extreme implication of the weakened commitment—infidelity. We found that pornography consumption corresponded to decreased commitment, which, in turn related to higher levels of infidelity.

{ Journal of Social and Clinical Psychology | PDF }

We’ve all had that experience of going purposefully from one room to another, only to get there and forget why we made the journey. Four years ago, researcher Gabriel Radvansky and his colleagues stripped this effect down, showing that the simple act of passing through a doorway induces forgetting.

Now psychologists at Knox College, USA, have taken things further, demonstrating that merely imagining walking through a doorway is enough to trigger increased forgetfulness.

{ BPS | Continue reading }

photo { Barbara Klemm, Louvre, Paris, 1987 }

In an experiment researchers showed that the human brain uses memories to make predictions about what it expects to find in familiar contexts. When those subconscious predictions are shown to be wrong, the related memories are weakened and are more likely to be forgotten. And the greater the error, the more likely you are to forget the memory.

{ Lunatic Laboratories | Continue reading }