The symbol for love is the heart, but the brain may be more accurate.
- How love makes us feel can only be defined on an individual basis, but what it does to the body, specifically the brain, is now less abstract thanks to science.
- One of the problems with early-stage attraction, according to anthropologist Helen Fisher, is that it activates parts of the brain that are linked to drive, craving, obsession, and motivation, while other regions that deal with decision-making shut down.
- Dr. Fisher, professor Ted Fischer, and psychiatrist Gail Saltz explain the different types of love, explore the neuroscience of love and attraction, and share tips for sustaining relationships that are healthy and mutually beneficial.
A new study suggests that reports of the impending infertility of the human male are greatly exaggerated.
- A new review of a famous study on declining sperm counts finds several flaws.
- The old report makes unfounded assumptions, has faulty data, and tends toward panic.
- The new report does not rule out that sperm counts are going down, only that this could be quite normal.
Several years ago, a meta-analysis of studies on human fertility came out warning us about the declining sperm counts of Western men. It was widely shared, and its findings were featured on the covers of popular magazines. Indeed, its findings were alarming: a nearly 60 percent decline in sperm per milliliter since 1973 with no end in sight. It was only a matter of time, the authors argued, until men were firing blanks, literally.
Well… never mind.
It turns out that the impending demise of humanity was greatly exaggerated. As the predicted infertility wave crashed upon us, there was neither a great rush of men to fertility clinics nor a sudden dearth of new babies. The only discussions about population decline focus on urbanization and the fact that people choose not to have kids rather than not being able to have them.
Now, a new analysis of the 2017 study says that lower sperm counts is nothing to be surprised by. Published in Human Fertility, its authors point to flaws in the original paper's data and interpretation. They suggest a better and smarter reanalysis.
Counting tiny things is difficult
The original 2017 report analyzed 185 studies on 43,000 men and their reproductive health. Its findings were clear: "a significant decline in sperm counts… between 1973 and 2011, driven by a 50-60 percent decline among men unselected by fertility from North America, Europe, Australia and New Zealand."
However, the new analysis points out flaws in the data. As many as a third of the men in the studies were of unknown age, an important factor in reproductive health. In 45 percent of cases, the year of the sample collection was unknown- a big detail to miss in a study measuring change over time. The quality controls and conditions for sample collection and analysis vary widely from study to study, which likely influenced the measured sperm counts in the samples.
Another study from 2013 also points out that the methods for determining sperm count were only standardized in the 1980s, which occurred after some of the data points were collected for the original study. It is entirely possible that the early studies gave inaccurately high sperm counts.
This is not to say that the 2017 paper is entirely useless; it had a much more rigorous methodology than previous studies on the subject, which also claimed to identify a decline in sperm counts. However, the original study had more problems.
Garbage in, garbage out
Predictable as always, the media went crazy. Discussions of the decline of masculinity took off, both in mainstream and less-than-reputable forums; concerns about the imagined feminizing traits of soy products continued to increase; and the authors of the original study were called upon to discuss the findings themselves in a number of articles.
However, as this new review points out, some of the findings of that meta-analysis are debatable at best. For example, the 2017 report suggests that "declining mean [sperm count] implies that an increasing proportion of men have sperm counts below any given threshold for sub-fertility or infertility," despite little empirical evidence that this is the case.
The WHO offers a large range for what it considers to be a healthy sperm count, from 15 to 250 million sperm per milliliter. The benefits to fertility above a count of 40 million are seen as minimal, and the original study found a mean sperm concentration of 47 million sperm per milliliter.
Healthy sperm, healthy man?
The claim that sperm count is evidence of larger health problems is also scrutinized in this new article. While it is true that many major health problems can impact reproductive health, there is little evidence that it is the "canary in the coal mine" for overall well-being. A number of studies suggest that any relation between lifestyle choices and this part of reproductive health is limited at best.
Lastly, ideas that environmental factors could be at play have been debunked since 2017. While the original paper considered the idea that pollutants, especially from plastics, could be at fault, it is now known that this kind of pollution is worse in the parts of the world that the original paper observed higher sperm counts in (i.e., non-Western nations).
There never was a male fertility crisis
The authors of the new review do not deny that some measurements are showing lower sperm counts, but they do question the claim that this is catastrophic or part of a larger pathological issue. They propose a new interpretation of the data. Dubbed the "Sperm Count Biovariability hypothesis," it is summarized as:
"Sperm count varies within a wide range, much of which can be considered non-pathological and species-typical. Above a critical threshold, more is not necessarily an indicator of better health or higher probability of fertility relative to less. Sperm count varies across bodies, ecologies, and time periods. Knowledge about the relationship between individual and population sperm count and life-historical and ecological factors is critical to interpreting trends in average sperm counts and their relationships to human health and fertility."
Still, the authors note that lower sperm counts "could decline due to negative environmental exposures, or that this may carry implications for men's health and fertility."
However, they disagree that the decline in absolute sperm count is necessarily a bad sign for men's health and fertility. We aren't at civilization ending catastrophe just yet.
The tiny swimmers appear to transmit signals that "persuade" the female body to have a baby.
The following article was originally published on our sister site, Freethink.
New research suggests that sperm play a bigger role in pregnancy than previously believed, not only fertilizing the egg, but also "persuading" the female body to accept it.
Revisiting sex ed: Human reproduction typically starts with sperm traveling via seminal fluid to an egg and fertilizing it. That creates a zygote, which can then attach to the wall of the uterus and begin the process of developing into a baby.
Implantation isn't a given, though. The woman's immune system may reject the fertilized egg as something "foreign" and prevent her from becoming pregnant.
Persuasive swimmers: Past research has shown that seminal fluid contains proteins that dampen this immune response, encouraging the woman's body to accept the zygote and the pregnancy.
Now, researchers at the University of Adelaide have discovered that sperm send their own signals designed to persuade the woman's body.
"This overturns our current understanding of what sperm are capable of," project leader Sarah Robertson said in a press release. "They are not just carriers of genetic material, but also agents for convincing the female to invest reproductive resources with that male."
The study: For a new study, female mice were mated with males who produced sperm and males who'd been vasectomized (meaning they produced seminal fluid without sperm).
Based on changes in the expression of different genes in the females' uteruses, the researchers determined that the sperm-producing mice prompted a stronger immune tolerance in their mates than the vasectomized rodents.
By introducing male sperm to female cells in the lab, the researchers were able to confirm that the sperm was directly responsible for the changes.
Why it matters: Infertility is a common issue, affecting tens of millions of couples across the globe, and problems such as recurrent miscarriage, preeclampsia, and stillbirth have all been linked to the female immune response during reproduction.
Now that we know that sperm can affect that immune response, researchers may be able to identify new ways to treat infertility — potentially helping some couples conceive and give birth to healthy babies.
Freethink would love to hear from you! If you have a comment about this article or if you have a tip for a future Freethink story, please email us at email@example.com.
These Roman Emperors were infamous for their debauchery and cruelty.
- Roman Emperors were known for their excesses and violent behavior.
- From Caligula to Elagabalus, the emperors exercised total power in the service of their often-strange desires.
- Most of these emperors met violent ends themselves.
We rightfully complain about many of our politicians and leaders today, but historically speaking, humanity has seen much worse. Arguably no set of rulers has been as debauched, ingenious in their cruelty, and prone to excess as the Roman Emperors.
While this list is certainly not exhaustive, here are seven Roman rulers who were perhaps the worst of the worst in what was one of the largest empires that ever existed, lasting for over a thousand years.
Officially known as Gaius (Gaius Caesar Augustus Germanicus), Caligula was the third Roman Emperor, ruling from 37 to 41 AD. He acquired the nickname "Caligula" (meaning "little [soldier's] boot") from his father's soldiers during a campaign.
While recognized for some positive measures in the early days of his rule, he became famous throughout the ages as an absolutely insane emperor, who killed anyone when it pleased him, spent exorbitantly, was obsessed with perverse sex, and proclaimed himself to be a living god.
Caligula gives his horse Incitatus a drink during a banquet. Credit: An engraving by Persichini from a drawing by Pinelli, from "The History of the Roman Emperors" from Augustus to Constantine, by Jean Baptiste Louis Crevier. 1836.
Among his litany of misdeeds, according to the accounts of Caligula's contemporaries Philo of Alexandria and Seneca the Younger, he slept with whomever he wanted, brazenly taking other men's wives (even on their wedding nights) and publicly talking about it.
He also had an insatiable blood thirst, killing for mere amusement. Once, as reports historian Suetonius, when the bridge across the sea at Puteoli was being blessed, he had a number of spectators who were there to inspect it thrown off into the water. When some tried to cling to the ships' rudders, Caligula had them dislodged with hooks and oars so they would drown. On another occasion, he got so bored that he had his guards throw a whole section of the audience into the arena during the intermission so they would be eaten by wild beasts. He also allegedly executed two consuls who forgot his birthday.
Suetonius relayed further atrocities of the mad emperor's character, writing that Caligula "frequently had trials by torture held in his presence while he was eating or otherwise enjoying himself; and kept an expert headsman in readiness to decapitate the prisoners brought in from gaol." One particular form of torture associated with Caligula involved having people sawed in half.
He caused mass starvation and purposefully wasted money and resources, like making his troops stage fake battles just for theater. If that wasn't enough, he turned his palace into a brothel and was accused of incest with his sisters, Agrippina the Younger, Drusilla, and Livilla, whom he also prostituted to other men. Perhaps most famously, he was planning to appoint his favorite horse Incitatus a consul and went as far as making the horse into a priest.
In early 41 AD, Caligula was assassinated by a conspiracy of Praetorian Guard officers, senators, and other members of the court.
Fully named Nero Claudius Caesar, Nero ruled from 54 to 68 AD and was arguably an even worse madman than his uncle Caligula. He had his step-brother Britannicus killed, his wife Octavia executed, and his mother Agrippina stabbed and murdered. He personally kicked to death his lover Poppeaea while she was pregnant with his child — a horrific action the Roman historian Tacitus depicted as "a casual outburst of rage."
He spent exorbitantly and built a 100-foot-tall bronze statue of himself called the Colossus Neronis.
He is also remembered for being strangely obsessed with music. He sang and played the lyre, although it's not likely he really fiddled as Rome burned in what is a popular myth about this crazed tyrant. As misplaced retribution for the fire which burned down a sizable portion of Rome in the year 64, he executed scores of early Christians, some of them outfitted in animal skins and brutalized by dogs, with others burned at the stake.
He died by suicide.
Roman Emperor Nero in the burning ruins of Rome. July 64 AD.Credit: From an original painting by S.J. Ferris. (Photo by Kean Collection / Getty Images)
Like some of his counterparts, Commodus (a.k.a. Lucius Aelius Aurelius Commodus) thought he was a god — in his case, a reincarnation of the Greek demigod Hercules. Ruling from 176 to 192 AD, he was also known for his debauched ways and strange stunts that seemed designed to affirm his divine status. Numerous statues around the empire showed him as Hercules, a warrior who fought both men and beasts. He fought hundreds of exotic animals in an arena like a gladiator, confusing and terrifying his subjects. Once, he killed 100 lions in a single day.
Emperor Commodus (Joaquin Phoenix) questions the loyalty of his sister Lucilla (Connie Nielsen) In Dreamworks Pictures' and Universal Pictures' Oscar-winning drama "Gladiator," directed by Ridley Scott.Credit: Photo By Getty Images
The burning desire to kill living creatures as a gladiator for the New Year's Day celebrations in 193 AD brought about his demise. After Commodus shot hundreds of animals with arrows and javelins every morning as part of the Plebeian Games leading up to New Year's, his fitness coach (aptly named Narcissus), choked the emperor to death in his bath.
Officially named Marcus Aurelius Antoninus II, Elagabalus's nickname comes from his priesthood in the cult of the Syrian god Elagabal. Ruling as emperor from 218 to 222 AD, he was so devoted to the cult, which he tried to spread in Rome, that he had himself circumcised to prove his dedication. He further offended the religious sensitivities of his compatriots by essentially replacing the main Roman god Jupiter with Elagabal as the chief deity. In another nod to his convictions, he installed on Palatine Hill a cone-like fetish made of black stone as a symbol of the Syrian sun god Sol Invictus Elagabalus.
His sexual proclivities were also not well received at the time. He was likely transgender (wearing makeup and wigs), had five marriages, and was quite open about his male lovers. According to the Roman historian (and the emperor's contemporary) Cassius Dio, Elagabalus prostituted himself in brothels and taverns and was one of the first historical figures on record to be looking for sex reassignment surgery.
He was eventually murdered in 222 in an assassination plot engineered by his own grandmother Julia Maesa.
Emperor for just eight months, from April 19th to December 20th of the year 69 AD, Vitellius made some key administrative contributions to the empire but is ultimately remembered as a cruel glutton. He was described by Suetonius as overly fond of eating and drinking, to the point where he would eat at banquets four times a day while sending out the Roman navy to get him rare foods. He also had little social grace, inviting himself over to the houses of different noblemen to eat at their banquets, too.
Vitellius dragged through the streets of Rome.Credit: Georges Rochegrosse. 1883.
He was also quite vicious and reportedly either had his own mother starved to death or approved a poison with which she committed suicide.
Vitellius was ultimately murdered in brutal fashion by supporters of the rival emperor Vespasian, who dragged him through Rome's streets, then likely beheaded him and threw his body into the Tiber river. "Yet I was once your emperor," were supposedly his last words, wrote historian Cassius Dio.
Marcus Aurelius Antoninus I ruled Rome from 211 to 217 AD on his own (while previously co-ruling with his father Septimius Severus from 198). "Caracalla"' was his nickname, referencing a hooded coat from Gaul that he brought into Roman fashion.
He started off his rise to individual power by murdering his younger brother Geta, who was named co-heir by their father. Caracalla's bloodthirsty tyranny didn't stop there. He wiped out Geta's supporters and was known to execute any opponents to his or Roman rule. For instance, he slaughtered up to 20,000 citizens of Alexandria after a local theatrical satire dared to mock him.
Geta Dying in His Mother's Arms.Credit: Jacques Pajou (1766-1828)
One of the positive outcomes of his rule was the Edict of Caracalla, which gave Roman citizenship to all free men in the empire. He was also known for building gigantic baths.
Like others on this list, Caracalla met a brutal end, being assassinated by army officers, including the Praetorian prefect Opellius Macrinus, who installed himself as the next emperor.
As the second emperor, Tiberius (ruling from 42 BC to 16 AD) is known for a number of accomplishments, especially his military exploits. He was one of the Roman Empire's most successful generals, conquering Pannonia, Dalmatia, Raetia, and parts of Germania.
He was also remembered by his contemporaries as a rather sullen, perverse, and angry man. In the chapter on his life from The Lives of the Twelve Caesars by the historian Suetonius, Tiberius is said to have been disliked from an early age for his personality by even his family. Suetonius wrote that his mother Antonia often called him "an abortion of a man, that had been only begun, but never finished, by nature."
"Orgy of the Times of Tiberius on Capri".Painting by Henryk Siemiradzki. 1881.
Suetonius also paints a damning picture of Tiberius after he retreated from public life to the island of Capri. His years on the island would put Jeffrey Epstein to shame. A horrendous pedophile, Tiberius had a reputation for "depravities that one can hardly bear to tell or be told, let alone believe," Suetonius wrote, describing how "in Capri's woods and groves he arranged a number of nooks of venery where boys and girls got up as Pans and nymphs solicited outside bowers and grottoes: people openly called this 'the old goat's garden,' punning on the island's name."
There's much, much more — far too salacious and, frankly, disgusting to repeat here. For the intrepid or morbidly curious reader, here's a link for more information.
After he died, Tiberius was fittingly succeeded in emperorship by his grandnephew and adopted grandson Caligula.
A study finds that sexual regret doesn't change how we behave in the future.
- Researchers from the Norwegian University of Science and Technology investigate the degree to which regret regarding sexual encounters makes us modify our behavior.
- Women more often have regrets about encounters that occurred, while men regret the ones that didn't.
- According to the study, people keep doing what they've been doing and continue to have the same regrets.
When it comes to sexual encounters, both women and men may be left with feelings of regret in the fading afterglow. Women, according to recent research, are more likely to experience "action regret," wishing they hadn't had sex. Men, on the other hand, are more likely to report "inaction regret" if they feel they've passed up on a sexual opportunity.
Both may experience regret, says a new study, but not so much that it changes their behavior going forward.
Speaking to Norwegian SciTech, the lead author of the study, Leif Edward Ottesen Kennair of Norwegian University of Science and Technology (NTNU), says, "For the most part, people continue with the same sexual behavior and the same level of regret."
The evolutionary value of emotion
Credit: Morgan Lane/Unsplash
"We wanted to examine if their level of regret contributed to a change in behavior the next time around," says senior author Mons Bendixen, who collaborated with Kennair and postdoctoral fellow Trond Viggo Grøntvedt.
Explains Kennair, "A lot of emotions are functional, like disgust that protects against infection and fear that protects against danger. An evolutionary approach has helped us understand anxiety by understanding the function of fear: fight-flight-freeze is about avoiding danger and defending ourselves against it."
The authors say that psychologists generally assume that emotions such as regret serve an evolutionary purpose — they keep us from repeating undesirable behavior.
"Researchers," says Grøntvedt, "have found that most people believe this is true for regret. They assume that regret is actually a helpful negative feeling. People assume it guides them not to repeat what they regretted."
The flexibility of regret
Credit: Priscilla Du Preeze/Unsplash
To see if sexual regret does actually change people's behavior, the researchers invited NTNU students to complete an anonymized web questionnaire about sexual regret. Prospective participants were told:
"We invite you to participate in a research project that examines students' thoughts and feelings after having had casual sex (intercourse), and what factors that may affect these… Some of the questions are sensitive and relate to sexual acts and choices you may have made. Responding may cause some discomfort and embarrassment, and we recommend that all participants sit in an uninterrupted location when answering the questions."
Individuals who agreed to participate were asked to fill out the survey two times, 4.5 months apart. The volunteers were between 18 and 30 years of age. For the first pass at the questionnaire, 529 students, 63.2 percent of whom were female, participated. Just 283 people completed the questionnaire both times.
The questionnaire revealed a resounding, "Nope!" Four and a half months later, individuals had continued to hook up or not hook up in the same way they had at the start of the study. They also exhibited the same level of regret.
Credit: Phix Nguyễn/Unsplash
Kennair admits, "We are not that surprised. If regret helped, would not most sinners eventually become saints? What do you regret the most often? Has it changed your behavior?"
The researchers suggest that, as they suspected at the outset of the project, regret is an emotion that's adaptive, with its impact on behavior dependent on context. In the case of sexual regret, there may be a disconnect between what we think we should want and what we really want.
It may also be that habit simply overpowers regret. Previous studies have found that habits create ever-stronger neural pathways — it's why people often repeat mistakes. The idea is that making a mistake a first time creates a neural pathway to which we increasingly and unconsciously gravitate each time we repeat the error.
Kennair cautions, however, against getting too hung up on sexual regrets.
"And yet," he says, "there are some folks who think that depressive ruminating and worry are a good idea. But the way we treat depression and generalized anxiety disorders is by helping people to stop ruminating and to stop worrying. Not everything people do, think or feel is an evolutionary adaptation — sometimes it is not appropriate either."