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
A common (sexist) stereotype proposes that women behave irrationally in certain phases of their menstrual cycle (e.g., hysteria). And in fact, many studies have now shown that women do behave differently when they are ovulating—from wearing red to being more likely to vote for Obama. Here, the researchers tested a) whether women are overall more or less economically rational than men (measured by the consistency of their choices and by performance on simulated gambling tasks), and b) whether this rationality varies over the menstrual cycle. Refuting all stereotypes, the authors found that “despite large fluctuations in hormone levels, women are as technically rational in their choice behavior as their male counterparts at all phases of the menstrual cycle. However…during ovulation women are less loss averse than men and therefore more economically rational than men in this regard.” Perhaps this means Janet should be the first in a long line of female chairs of the Fed?
“It is well known that hormones affect both brain and behavior, but less is known about the extent to which hormones affect economic decision-making. Numerous studies demonstrate gender differences in attitudes to risk and loss in financial decision-making, often finding that women are more loss and risk averse than men. It is unclear what drives these effects and whether cyclically varying hormonal differences between men and women contribute to differences in economic preferences. We focus here on how economic rationality and preferences change as a function of menstrual cycle phase in women. We tested adherence to the Generalized Axiom of Revealed Preference (GARP), the standard test of economic rationality. If choices satisfy GARP then there exists a well-behaved utility function that the subject’s decisions maximize. We also examined whether risk attitudes and loss aversion change as a function of cycle phase. Read More
Although many people believe that dogs can read their owners’ emotions, it was only recently shown that dogs can visually differentiate between happiness and anger. In fact, they are the first animals shown to discriminate emotions in another species. This study extends this line of research, adding an auditory component—they test whether dogs can match visual and sound representation of emotions. The researchers showed the pooches a face and either a concordant (matching) or discordant sound—for example, a happy face with an angry tone of voice, or a growling dog face with a happy bark. The dogs spent more time looking at the congruent pairs, indicating that they can categorize and integrate multiple emotional cues, a skill previously shown only in humans. (Be sure to check out Figure 1 below for the happy and angry faces used in the study.)
“The perception of emotional expressions allows animals to evaluate the social intentions and motivations of each other. This usually takes place within species; however, in the case of domestic dogs, it might be advantageous to recognize the emotions of humans as well as other dogs. In this sense, the combination of visual and auditory cues to categorize others’ emotions facilitates the information processing and indicates high-level cognitive representations. Using a cross-modal preferential looking paradigm, we presented dogs with either human or dog faces with different emotional valences (happy/playful versus angry/aggressive) paired with a single vocalization from the same individual with either a positive or negative valence or Brownian noise. Read More
For this week’s Flashback Friday, we’re revisiting a post from the old NCBI ROFL blog. Back in the day we were mostly writing for our fellow scientists, so we simply posted the abstract of the research article and let our readers make of it what they would. Although the result was was hit or miss with our lay readers (which is why we ended up writing a introductory blurb for our Seriously, Science? posts), we think this one is definitely a “hit”. But whether it should be read by most people… well, we’ll leave that to you to decide!
“This study aimed to assess the trajectory of breast displacement in 3 dimensions during walking and running gait, as this may improve bra design and has yet to be reported. Read More
When it comes to playing the odds, there are times when gambling feels more enticing than others. But is there a pattern to when people indulge in games of luck and when they abstain? Well, according to this study, there is! Apparently, when other circumstances dictated by “luck” are going well, people are more likely to play the lottery. Specifically, they found that people are more likely to play the lottery during a long string of sunny days, or when a local sports team is playing well. So, if you don’t want to share the pile of money with another winning ticket, your best bet may be to play when the weather’s bad or the Yankees are losing.
“Positive mood can affect a person’s tendency to gamble, possibly because positive mood fosters unrealistic optimism. At the same time, unexpected positive outcomes, often called prediction errors, influence mood. Read More
Relationships are complicated. And that’s true for both the platonic as well as the romantic kind. But when the two overlap, things can get very complicated in subtle and interesting ways, like the results from this study. It’s known that men behave differently towards women when they are fertile. For example, women get bigger tips for lap dances when ovulating. But here, researchers delved in to how fertile and non-fertile women interact. In particular, they wondered whether women would be more likely to try to protect their mates from fertile women versus non-ovulating women. It turns out that, yes, they do… but only if their partners are “highly desirable”!
“For women, forming close, cooperative relationships with other women at once poses important opportunities and possible threats—including to mate retention. To maximize the benefits and minimize the costs of same-sex social relationships, we propose that women’s mate guarding is functionally flexible and that women are sensitive to both interpersonal and contextual cues indicating whether other women might be likely and effective mate poachers. Read More
We all like to believe that, at least in fantasy fiction, the good characters win out because they are… well, good. But maybe there is another, simpler, explanation. Maybe it’s because the evil characters are weakened by a deficiency in vitamin D, which our bodies make when exposed to sunlight. Good thing there weren’t multivitamins in Middle Earth.
“OBJECTIVE: Vitamin D has been proposed to have beneficial effects in a wide range of contexts. We investigate the hypothesis that vitamin D deficiency, caused by both aversion to sunlight and unwholesome diet, could also be a significant contributor to the triumph of good over evil in fantasy literature. Read More
Humans are funny creatures. We go to great lengths to prolong our lives and prevent injury, from taking multivitamins to wearing bicycle helmets. Yet, as this study shows, these same behaviors actually make us feel so invulnerable that we take more risks than we would otherwise. Here, the researchers showed that even people NOT riding bicycles were more likely to take risks if wearing a helmet rather than a baseball cap. Not only that, but they take risks that would not be made safer by wearing the helmet (e.g., risking money in a video game). A similar study found that people who had taken a multivitamin were more likely to want to eat junk food an exercise less. Maybe we’d all be better off just taking our chances?
“Humans adapt their risk-taking behavior on the basis of perceptions of safety; this risk-compensation phenomenon is typified by people taking increased risks when using protective equipment. Existing studies have looked at people who know they are using safety equipment and have specifically focused on changes in behaviors for which that equipment might reduce risk. Here, we demonstrated that risk taking increases in people who are not explicitly aware they are wearing protective equipment; furthermore, this happens for behaviors that could not be made safer by that equipment. Read More
If you live in the middle of a city, you probably think that you won’t have any problems with access to medical care in an emergency. Well, think again: according to this retrospective study of people who had heart attacks in high-rise buildings in Toronto, people on the upper floors were much less likely to survive. In fact, “In an analysis by floor, survival was 0.9% above floor 16 (i.e., below the 1% threshold for futility), and there were no survivors above the 25th floor.” (This is compared to 4.2% survival below the 3rd floor – still not great.) In other words, if you live above the 16th floor, the paramedics probably shouldn’t bother, and if you live above the 25th floor, well… God speed.
“Background: increasing number of people living in high-rise buildings presents unique challenges to care and may cause delays for 911-initiated first responders (including paramedics and fire department personnel) responding to calls for out-of-hospital cardiac arrest. We examined the relation between floor of patient contact and survival after cardiac arrest in residential buildings.
Methods: We conducted a retrospective observational study using data from the Toronto Regional RescuNet Epistry database for the period January 2007 to December 2012. We included all adult patients (≥ 18 yr) with out-of-hospital cardiac arrest of no obvious cause who were treated in private residences. We excluded cardiac arrests witnessed by 911-initiated first responders and those with an obvious cause. We used multivariable logistic regression to determine the effect on survival of the floor of patient contact, with adjustment for standard Utstein variables.
Results: During the study period, 7842 cases of out-of-hospital cardiac arrest met the inclusion criteria, of which 5998 (76.5%) occurred below the third floor and 1844 (23.5%) occurred on the third floor or higher. Survival was greater on the lower floors (4.2% v. 2.6%, p = 0.002). Lower adjusted survival to hospital discharge was independently associated with higher floor of patient contact, older age, male sex and longer 911 response time. In an analysis by floor, survival was 0.9% above floor 16 (i.e., below the 1% threshold for futility), and there were no survivors above the 25th floor.
Interpretation: In high-rise buildings, the survival rate after out-of-hospital cardiac arrest was lower for patients residing on higher floors. Interventions aimed at shortening response times to treatment of cardiac arrest in high-rise buildings may increase survival.”
Having sex more than once a week doesn’t make you any happier.
Want to know how long you’ll live? Ask your friends!
Are people who dream about murder more likely to kill someone in real life?
If there were ever a study that supported the stereotype of the cold-hearted scientist, this might be it. Thank goodness it was apparently written in jest, along the lines of the British Medical Journal’s annual Christmas issue. But the “study” has still taken the internet by storm, because, well… it’s a bit nuts. It reports a series of experiments in which toddlers are inflicted with booboos, and tested directly whether a mother’s kiss would make it better. And how did they inflict booboos, you ask? Well, here’s a long quote directly from the Materials and Methods, because anything else wouldn’t do it justice:
To induce head boo-boos, a piece of chocolate was placed under a low table edge and the child would be allowed to crawl to the candy. Invariably, the child would then stand to eat the chocolate and would strike his or her head on the table edge. All tables were constructed of soft wood (pine or fir) and edges were appropriately rounded enough to guarantee that skin would not be broken. Hand boo-boos were induced by placing a favourite object (lovey) of the child just out of reach on a counter behind a heated coil. Attempts to obtain the lovey would result in a noxious thermal stimulus to the fingertips.
You just can’t make this stuff up! Except, apparently, in this case…
“BACKGROUND: The practice of maternal kissing of minor injuries of childhood (boo-boos), though widely endorsed and practised, has never been demonstrated to be of benefit to children.
OBJECTIVE: To determine the efficacy, if any, of maternal kissing of boo-boos in toddlers.
DESIGN: Randomized, controlled and double-blinded study of children with experimentally induced minor injuries. Control arms included both no intervention group and ‘sham’ (non-maternal) kissing. Children were blinded to the identity of the kisser in both the maternal and sham control groups.
SETTING: Outpatient research clinics in Ottawa, Canada.
PARTICIPANTS: 943 maternal-toddler pairs recruited from the community.
MEASUREMENTS: Toddler Discomfort Index (TDI) pre-injury, 1 and 5 minutes post-injury.
RESULTS: One-minute and 5-minute TDI scores did not differ significantly between the maternal and sham kiss groups. Both of these groups had significantly higher TDI scores at 5 minutes compared to the no intervention group.
CONCLUSIONS: Maternal kissing of boo-boos confers no benefit on children with minor traumatic injuries compared to both no intervention and sham kissing. In fact, children in the maternal kissing group were significantly more distressed at 5 minutes than were children in the no intervention group. The practice of maternal kissing of boo-boos is not supported by the evidence and we recommend a moratorium on the practice.”
NCBI ROFL: Children smelling man-sweat… for science!
NCBI ROFL: Freud’s take on doctors treating their own children is (surprise!) disturbing.
NCBI ROFL: How scaring small children can help you lose weight.