It’s clear that men can have more children than women, but can they have hundreds of children? Here, scientists created a computer simulation to determine how many times a day the 17th-century Moroccan Emperor Moulay Ismael would have had to have sex to have his reported brood of 888 kids. Accounting for factors ranging from sperm aging and ovulation to Moulay falling in love and having favorites, they found that the Emperor needed to get frisky 1-2 times a day and have a harem of at least 65 women to achieve his plentiful progeny.
The Case of Moulay Ismael – Fact or Fancy?
“Textbooks on evolutionary psychology and biology cite the case of the Sharifian Emperor of Morocco, Moulay Ismael the Bloodthirsty (1672–1727) who was supposed to have sired 888 children. This example for male reproduction has been challenged and led to a still unresolved discussion. The scientific debate is shaped by assumptions about reproductive constraints which cannot be tested directly—and the figures used are sometimes arbitrary. Therefore we developed a computer simulation which tests how many copulations per day were necessary to reach the reported reproductive outcome. Read More
Few things are as entertaining as watching animals on treadmills. Although Penguins might be the cutest, these ants are pretty fun, too. Here, researchers set up a hollow styrofoam ball floating on a stream of air as a treadmill for desert ants. To keep the ants from wandering (or simply falling) off the treadmill, the scientists glued the thorax to a small pin. They then were able to precisely track the animals’ movements and behavior as they navigated to their nests. Check out the video (below) to see the ants in action!
“Air-cushioned spheres are widely used as treadmills to study behavioural and neurophysiological questions in numerous species. We describe an improved spherical treadmill design that reliably registers the path and walking behaviour of an animal walking on top of the sphere. The simple and robust set-up consists of a very light hollowed styrofoam ball supported by an air stream in a hollow half sphere and can be used indoors and outdoors. Two optical mouse sensors provided with lenses of 4.6 mm focal length detect the motion of the sphere with a temporal resolution of more than 200 frames s−1 and a spatial resolution of less than 0.2 mm. Read More
Given all the money spent on advertising, it’s no wonder there are stereotypes about iPhone and Android users. But are these real? Is there anything you can predict about me just from knowing whether I use an iPhone or Android (and vice versa – can you predict my phone choice from my personality)? Well, according to these researchers, there really are population differences between iPhone and Android users: if I told them I used an iPhone, they would guess that I’m younger, female, and “increasingly concerned about [my] smartphone being viewed as a status object.” Little do they know that my phone is 4 years old and has had a smashed screen for months. Ha!
“Android and iPhone devices account for over 90 percent of all smartphones sold worldwide. Despite being very similar in functionality, current discourse and marketing campaigns suggest that key individual differences exist between users of these two devices; however, this has never been investigated empirically. Read More
If you’re like most people, you probably think that looks are mostly genetic–either you’re genetically “blessed” with good looks, or you’re not. But apparently it’s not as simple as that. According to this study, facial attractiveness in high school yearbook photographs increases with paternal education and parental income, “with the latter effect being stronger for female subjects.” In other words, rich kids tend to be more attractive, and especially girls. Whether the parents themselves being rich was related to their looks (which might make the effect genetic after all)…well, we’ll leave that for another study.
“Socio-economic conditions during early life are known to affect later life outcomes such as health or social success. We investigated whether family socio-economic background may also affect facial attractiveness. We used the Wisconsin Longitudinal Study (n = 8434) to analyze the association between an individual’s parental socio-economic background (in terms of father’s highest education and parental income) and that individual’s facial attractiveness (estimated by rating of high school yearbook photographs when subjects were between 17 and 20 years old), controlling for subjects’ sex, year of birth, and father’s age at subjects’ birth. Read More
Add this to the long list of reasons why daylight savings time should be abolished: according to this study, it could cause judges to dole out harsher sentences. More specifically, these researchers found that sleep-deprived judges (in this case, due to the shift to daylight savings time in the spring) gave out 5% longer sentences compared with well-rested judges. So there you have it: just as we hope justice is blind, we should also hope it got enough sleep last night.
“The degree of punishment assigned to criminals is of pivotal importance for the maintenance of social order and cooperation. Nonetheless, the amount of punishment assigned to transgressors can be affected by factors other than the content of the transgressions. We propose that sleep deprivation in judges increases the severity of their sentences. Read More
They say that laughter is the best medicine. And these days, who wouldn’t benefit from a good laugh? Well, according to this study, your abs also benefit from laughing, even if that laughter is gotten by seemingly artificial means: laughter yoga. Honestly, if this youtube video is at all representative of a laughter yoga session, it looks pretty awesome. And it’s even a better ab workout than traditional crunches. WIN!
“Social, psychological, and physiological studies have provided evidence indicating that laughter imposes an increased demand on trunk muscles. It was the aim of this study to quantify the activation of trunk muscles during laughter yoga in comparison with crunch and back lifting exercises regarding the mean trunk muscle activity. Read More
File this under “reinforcing stereotypes“: these scientists use word clouds created from the Facebook messages of 75,000 people to reveal not only the differences between men and women (fighting, football and xbox vs. babies, emoticons, and shopping), but between introverts and extroverts (anime and computers vs. parties and ‘chillin’). If this hasn’t paralyzed you from depression, continue reading for a peek at the rest of the word clouds in all their glory. xD
“We analyzed 700 million words, phrases, and topic instances collected from the Facebook messages of 75,000 volunteers, who also took standard personality tests, and found striking variations in language with personality, gender, and age. In our open-vocabulary technique, the data itself drives a comprehensive exploration of language that distinguishes people, finding connections that are not captured with traditional closed-vocabulary word-category analyses. Our analyses shed new light on psychosocial processes yielding results that are face valid (e.g., subjects living in high elevations talk about the mountains), tie in with other research (e.g., neurotic people disproportionately use the phrase ‘sick of’ and the word ‘depressed’), suggest new hypotheses (e.g., an active life implies emotional stability), and give detailed insights (males use the possessive ‘my’ when mentioning their ‘wife’ or ‘girlfriend’ more often than females use ‘my’ with ‘husband’ or ‘boyfriend’). To date, this represents the largest study, by an order of magnitude, of language and personality.”
Bonus figure from the main text:
Why posting on Facebook could be good for you.
NCBI ROFL: The science of Facebook relationship status: It’s complicated.
NCBI ROFL: Mirror, mirror on my Facebook wall: effects of exposure to Facebook on self-esteem.
We’ve reported on several phone-related medical conditions, from “nomophobia” (fear of being out of cell phone contact) to the consequences of swallowing your phone, case and all. In this case study of two patients, doctors report yet another condition, which they call “transient smartphone blindness.” TSB is caused by a combination of lying on your side while looking at your phone in a dark room. The result is temporary blindness in one eye “due to differential bleaching of photopigment, with the viewing eye becoming light-adapted while the eye blocked by the pillow was becoming dark-adapted. Subsequently, with both eyes uncovered in the dark, the light-adapted eye was perceived to be ‘blind.'” Fortunately, the blindness only lasts for a few minutes — though these patients’ embarrassment at seeking extensive medical care because they looked at their phones in bed might last a bit longer.
“Transient monocular vision loss is a common clinical presentation, and the cause is not always thromboembolic.1 We present two cases in which careful history taking established a benign cause (for the case histories, see the Supplementary Appendix, available with the full text of this letter at NEJM.org).
A 22-year-old woman presented with a several months’ history of recurrent impaired vision in the right eye that occurred at night. The results of ophthalmic and cardiovascular examinations were normal. Vitamin A levels and the results of magnetic resonance angiography, echocardiography, and a thrombophilia screening were also normal. Read More
Urban legend has it that “all” of our paper currency is tainted with cocaine. These scientists decided to test whether this is true, and if so, how much of the drug is there. By testing over four thousand bills of various denominations gathered from 90 locations over more than a decade, they estimate that the “average” bill carries only 2.34 ng of cocaine (a tiny, tiny amount), but any given bill has ~15% chance of having more than 20 ng… which is still a tiny amount, but it’s there! Um… yay?!
The quantitation of cocaine on U.S. currency: survey and significance of the levels of contamination.
“It has long been suspected that the illicit distribution of cocaine in the United States has led to a large-scale contamination of the currency supply. To investigate the extent of contamination, 418 currency samples (4174 bills) were collected from 90 locations around the United States from 1993 to 2009. Read More
Everyone knows that pandas eat bamboo. But did you know that many of their closest relatives are carnivores? So how did the meat-eating ancestor of pandas become a vegetarian? According to this study, it may have had to do with the deactivation (technically known as “pseudogenization”) of an umami taste receptor gene. Umami is the taste that makes things like meat, soy sauce, and mushrooms extra yummy. Apparently, at some point in panda evolution, the umami receptor became non-functional. Based on how much the gene has changed, the authors calculate that this happened around the same time that pandas started eating bamboo. Whether it’s cause or effect is unclear, although the authors think the switch to bamboo may have happened before the gene was lost. Regardless, the loss of the gene reinforced the panda’s vegetarian diet because it made meat less delicious to the bears. Now if only we could make chocolate less delicious… wait, that’s a terrible idea!
“Although it belongs to the order Carnivora, the giant panda is a vegetarian with 99% of its diet being bamboo. The draft genome sequence of the giant panda shows that its umami taste receptor gene Tas1r1 is a pseudogene, prompting the proposal that the loss of the umami perception explains why the giant panda is herbivorous. Read More