It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Wednesday, March 12, 2025
Adolescent boys who experience violence have up to 8 times the odds of perpetrating physical and sexual intimate partner violence that same day, per South African study collecting real-time data over mobile phones
Credit: Kidman et al., 2025, PLOS One, CC-BY 4.0 (https://creativecommons.org/licenses/by/4.0/)
Adolescent boys who experience violence have up to 8 times the odds of perpetrating physical and sexual intimate partner violence that same day, per South African study collecting real-time data over mobile phones
Article title: Measuring real-time violence exposure and its impact on intimate partner violence perpetration among adolescents
Author countries: US, South Africa
Funding: Research reported in this publication was supported by the National Institute of Mental Health under Award R01MH119878. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. JD also received partial funding by the South African Medical Research Council (SAMRC). SV was partially supported by the Consortium for Advanced Research Training in Africa (CARTA).
Measuring real-time violence exposure and its impact on intimate partner violence perpetration among adolescents
Article Publication Date
12-Mar-2025
Critically endangered hawksbill turtles migrate up to 1,000km from nesting to foraging grounds in the Western Caribbean, riding with and against ocean currents to congregate in popular feeding hotspots
Article title: Inter-nesting area use, migratory routes, and foraging grounds for hawksbill turtles (Eretmochelys imbricata) in the Western Caribbean
Author countries: US, Honduras, Costa Rica
Funding: Funding for this project was provided by the Boyd Lyon Sea Turtle Fund to QDB, the Sonoma County Community Foundation to CED, the Fort Wayne Children's Zoo Conservation Fund and the Jack Schrey Distinguished Professor Funds to FVP, the USFWS Marine Turtle Conservation Fund Grant #611510 under the direction of Earl Possardt to SGD, the Department of Earth and Biological Sciences at Loma Linda University to SGD, as well as the California Turtle and Tortoise Club Inland Empire Chapter to SGD.
For those looking to climb the corporate ladder in the U.S., here’s an idea you might not have considered: debate training.
According to a new research paper, people who learn the basics of debate are more likely to advance to leadership roles in U.S. organizations, compared to those who do not receive this training. One key reason is that being equipped with debate skills makes people more assertive in the workplace.
“Debate training can promote leadership emergence and advancement by fostering individuals’ assertiveness, which is a key, valued leadership characteristic in U.S. organizations,” says MIT Associate Professor Jackson Lu, one of the scholars who conducted the study.
The research is based on two experiments and provides empirical insights into leadership development, a subject more often discussed anecdotally than studied systematically.
“Leadership development is a multi-billion-dollar industry, where people spend a lot of money trying to help individuals emerge as leaders,” Lu says. “But the public doesn’t actually know what would be effective, because there hasn’t been a lot of causal evidence. That’s exactly what we provide.”
The paper, “Breaking Ceilings: Debate Training Promotes Leadership Emergence by Increasing Assertiveness,” was published Monday in the Journal of Applied Psychology. The authors are Lu, an associate professor at the MIT Sloan School of Management; Michelle X. Zhao, an undergraduate student at the Olin Business School of Washington University in St. Louis; Hui Liao, a professor and assistant dean at the University of Maryland’s Robert H. Smith School of Business; and Lu Doris Zhang, a doctoral student at MIT Sloan.
Assertiveness in the attention economy
The researchers conducted two experiments. In the first, 471 employees in a Fortune 100 firm were randomly assigned to receive either nine weeks of debate training or no training. Examined 18 months later, those receiving debate training were more likely to have advanced to leadership roles, by about 12 percentage points. This effect was statistically explained by increased assertiveness among those with debate training.
The second experiment, conducted with 975 university participants, further tested the causal effects of debate training in a controlled setting. Participants were randomly assigned to receive debate training, an alternative non-debate training, or no training. Consistent with the first experiment, participants receiving the debate training were more likely to emerge as leaders in subsequent group activities, an effect statistically explained by their increased assertiveness.
“The inclusion of a non-debate training condition allowed us to causally claim that debate training, rather than just any training, improved assertiveness and increased leadership emergence,” Zhang says.
To some people, increasing assertiveness might not seem like an ideal recipe for success in an organizational setting, as it might seem likely to increase tensions or decrease cooperation. But as the authors note, the American Psychological Association conceptualizes assertiveness as “an adaptive style of communication in which individuals express their feelings and needs directly, while maintaining respect for others.”
Lu adds: “Assertiveness is conceptually different from aggressiveness. To speak up in meetings or classrooms, people don’t need to be aggressive jerks. You can ask questions politely, yet still effectively express opinions. Of course, that’s different from not saying anything at all.”
Moreover, in the contemporary world where we all must compete for attention, refined communication skills may be more important than ever.
“Whether it is cutting filler or mastering pacing, knowing how to assert our opinions helps us sound more leader-like,” Zhang says.
How firms identify leaders
The research also finds that debate training benefits people across demographics: Its impact was not significantly different for men or women, for those born in the U.S. or outside it, or for different ethnic groups.
However, the findings raise still other questions about how firms identify leaders. As the results show, individuals might have incentive to seek debate training and other general workplace skills. But how much responsibility do firms have to understand and recognize the many kinds of skills, beyond assertiveness, that employees may have?
“We emphasize that the onus of breaking leadership barriers should not fall on individuals themselves,” Lu says. “Organizations should also recognize and appreciate different communication and leadership styles in the workplace.”
Lu also notes that ongoing work is needed to understand if those firms are properly valuing the attributes of their own leaders.
“There is an important distinction between leadership emergence and leadership effectiveness,” Lu says. “Our paper looks at leadership emergence. It’s possible that people who are better listeners, who are more cooperative, and humbler, should also be selected for leadership positions because they are more effective leaders.”
This research was partly funded by the Society for Personality and Social Psychology.
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Written by Peter Dizikes, MIT News
Paper: “Breaking Ceilings: Debate Training Promotes Leadership Emergence by Increasing Assertiveness”
Carlo Maley is a researcher with the BiodesignCenter for Biocomputing, Security and Society, a professor with the School of Life Sciences and director of the Arizona Cancer Evolution Center.
Credit: The Biodesign Institute at Arizona State University
Researchers have long known that diet exerts a profound influence on health, including the risk of developing cancer. A new study, led by researchers at Arizona State University, explores the relationship between diet, blood sugar (specifically glucose) and cancer prevalence across a broad range of vertebrate species.
Surprisingly, the study found that birds, despite having significantly higher blood sugar levels and living longer than similarly sized mammals and reptiles, have lower cancer prevalence. It also revealed that primary carnivores — animals that mainly consume other vertebrates — are more prone to tumors than herbivores, particularly when domestication is considered.
The findings, published today in the journal Nature Communications, challenge existing assumptions and suggest that some species have evolved natural biological defenses against cancer. These defenses — such as metabolic adaptations and cellular protective mechanisms — could inspire new approaches to cancer prevention and treatment in humans.
“We knew that birds get less cancer than mammals, and they also have very high levels of glucose in their blood. That made us wonder if there was some connection,” study co-author Carlo Maley said.
The study examined data from up to 273 vertebrate species, analyzing their diet, average plasma sugar levels and cancer prevalence. A key finding was that birds, despite their high blood sugar, have lower cancer rates than mammals and reptiles.
This was unexpected because in humans and many other animals, high blood sugar is often linked to increased cancer risk. However, the study found that the link between plasma sugar levels and cancer prevalence did not hold consistently across all vertebrates. Instead, the trend was driven by broad differences among major groups — birds, mammals and reptiles. When researchers examined each group separately, they found no clear relationship between plasma sugar levels and cancer rates within those groups.
This suggests that birds may have evolved unique biological mechanisms that protect them from cancer despite high blood sugar levels — mechanisms absent in mammals and reptiles. Understanding these adaptations could offer valuable insights into cancer resistance.
“Future studies investigating the evolutionary history and mechanisms linking diet, plasma glucose levels and cancer prevalence across vertebrates would provide further clues about the observed diversity among species and inform strategies for more effective cancer prevention and treatment across vertebrates,” Kapsetaki said.
The role of diet
The researchers also investigated whether diet influences plasma sugar levels and cancer prevalence. While previous studies suggested that carnivores have a higher cancer risk than herbivores, this study across nonhuman vertebrates examined diet categories in greater detail, considering factors like the proportion of fruit, plants, invertebrates and vertebrate meat in an animal’s diet.
The study found no statistically significant link between diet and plasma sugar levels across nonhuman vertebrate species, suggesting that glucose regulation is likely influenced more by evolutionary and physiological adaptations than diet alone. While diet affects blood sugar levels in humans and some other species, it does not appear to be a universal rule across vertebrates.
One explanation is that different species have evolved distinct mechanisms to manage blood sugar, regardless of diet. For example, birds maintain high blood sugar despite diverse diets, ranging from nectar-rich to meat-based. Similarly, some carnivorous mammals have stable blood sugar levels despite protein-heavy diets, while certain herbivores show variability unrelated to their plant-based food intake.
“The lack of an overall connection between diet and blood sugar in the species examined in this study suggests that these animals are largely consuming foods designed for them as their diet was not manipulated for the study,” Sweazea said. “Even when our lab fed birds diets high in fat or sugar, which are known to increase blood sugar and cancer risk in humans, the birds show no changes in their blood sugar response. They are remarkably resilient animals.”
Although diet does not strongly influence blood sugar levels across species, it may still play a role in cancer risk. The study found that primary carnivores had a higher tumor prevalence than herbivores. One possible explanation is that harmful compounds accumulate in the food chain, making vertebrate meat consumption a potential risk for tumor development.
In addition, the researchers found that domesticated species tend to have a higher cancer prevalence, possibly due to reduced genetic diversity and weaker evolutionary pressures. This suggests that natural selection may help limit cancer in wild populations. However, while the study highlights patterns across species, it does not suggest that eating domesticated animals specifically increases cancer risk in humans.
Implications for human health
Although this study focused on nonhuman species, its findings may offer new insights into preventing cancer in people. Unlike birds — which seem to have evolved natural defenses against cancer despite high blood sugar levels — humans and other mammals do not show the same resistance.
The researchers propose that birds may have evolved unique cancer defenses, potentially related to their high metabolic rate, reliance on fat metabolism over glucose, and cellular adaptations that limit oxidative damage. Understanding these adaptations could provide valuable insights into how species evolve natural cancer defenses.
For now, the best advice for humans remains consistent with public health recommendations: Eat a balanced diet, avoid excessive processed and red meat, and manage blood sugar through a healthy lifestyle, including regular exercise. However, scientists will continue investigating whether nature’s cancer-resistant species can offer new solutions in the fight against the disease.
ITHACA, N.Y. -- In a scene toward the end of the 2006 film, “X-Men: The Last Stand,” a character claps and sends a shock wave that knocks out an opposing army.
Sunny Jung, professor of biological and environmental engineering in the College of Agriculture and Life Sciences, was intrigued.
“It made me curious about how the wave propagates when we clap our hands,” Jung said.
Jung is senior author of a study, published March 11 in Physical Review Research, that elucidates the complex physical mechanisms and fluid dynamics involved in a handclap, with potential applications in bioacoustics and personal identification, whereby a handclap could be used to identify someone.
“Clapping hands is a daily, human activity and form of communication,” Jung said. “We use it in religious rituals, or to express appreciation: to resonate ourselves and excite ourselves. We wanted to explore how we generate the sound depending on how we clap our hands.”
The researchers used high-speed cameras to track the hand motion, air flow and sound of 10 volunteers clapping, measuring the different frequencies when the size and shape of the cavity between hands changes: when clapping with cupped hands, flat hands or fingers to palm. They found the larger the cavity between palms, the lower the frequency of the clap, with the hands acting as a resonator – whereby the sound comes from the force of air through the hand’s cavity and the opening between the thumb and index finger.
“It’s the air column pushed by this jet flow of air coming out of the hand cavity that causes the disturbance in the air, and that’s the sound we hear,” said first author Yicong Fu, doctoral student in the field of mechanical engineering.
The researchers compared the human data to that produced with simplified replicas, as well as theoretical projections of how air would move through a traditional resonator, called a Helmholtz resonator.
“We confirmed both experimentally and computationally that the Helmholtz resonator can predict the frequency of the human handclap,” Fu said. “It’s a confirmation of this unifying principle that may be helpful in other fields, especially bioacoustics, because that principle may help explain all kinds of bioacoustics phenomena, especially those involving soft material collision and jet flow.”
“This is also a fundamental principle of the musical instrument,” Jung said, “that depending on the size of the cavity and the length of the neck opening, you create a different sound – we showed that this also applies to handclapping.”
Additionally, the researchers studied why claps are so short, compared to sound made through a traditional resonator, finding that the softness of the hands plays a role: the soft tissues of the hands vibrate after impact, absorbing energy and dampening the sound.
“When there’s more vibration in the material, the sound attenuates much more quickly,” Fu said. “So, if you want to get the attention of another person very far from you, and you want the sound to last longer, you might want to choose a certain type of handclapping shape that makes your hand more rigid.”
The research further opens the door to the idea of using a handclap as a personal identifier or signature; another of Jung’s students is testing whether a handclap could be used to take attendance in a class, for example.
“The handclap is actually a very characteristic thing, because we have different sizes of hand, techniques, different skin textures and softness – that all results in different sound performances,” Fu said. “Now that we understand the physics of it, we can use the sound to identify the person.”
Previous studies have investigated either the simplified theoretical mechanics behind the handclap or statistical analysis using human subjects, but the connection between the two is new. With an experimental setup that assessed sound and air flow; the size, shape and texture of the hand; and the force, speed and pressure of the clap, the researchers were able to capture multiple variables that incorporated materials science, fluid mechanics and acoustics.
“This is the most thorough study on this topic,” Fu said. “The way we set it up helped visualize the phenomena, and because it’s so comprehensive, we’re able to generate more knowledge from it.”
For Jung, the study also satisfies a curiosity. “This started as wanting to understand something I saw and something we do every day,” he said. “When I see something, I try to question why it happens.”
Co-authors include Akihito Kiyama, former postdoctoral researcher and now assistant professor at Saitama University in Japan; and Guoqin Liu and Likun Zhang at the University of Mississippi’s National Center for Physics and Astronomy.
The study was supported in part with funding from the National Science Foundation.
Video can be viewed and downloaded here: https://cornell.box.com/v/handclappingacoustics
