There are many things that can happen to a body between death and burial. A good example of this process is Weekend at Bernie’s. Bernie Lomax is murdered within the first twenty minutes of the movie, but he remains an important character as Richard and Larry feign that he is alive in order to continue to … Continue reading »... Read more »
André, A., Leahy, R., & Rottier, S. (2013) Cremated Human Remains Deposited in Two Phases: Evidence from the Necropolis of the Tuileries Site (Lyon, France: 2nd Century AD). International Journal of Osteoarchaeology. DOI: 10.1002/oa.2317
With increasing evidence for Mesoamerican influence at Chaco in recent years, it’s worth taking a close look at what was going on in Mesoamerica itself during the Chacoan era. As I’ve mentioned before, there is some reason to believe that the most likely area to look to for direct influence in the Southwest is West Mexico, [...]... Read more »
The Shambulance is an occasional series in which I try to find the truth about bogus or overhyped health products. Helping me keep the Shambulance on course are Steven Swoap and Daniel Lynch, both biology professors at Williams College.
Sticking a Q-tip up one’s nose is not the source of many great insights. Yet it’s how an American doctor in the early 20th century developed the theory that became modern reflexology. He would be proud—though maybe a little confused—to see people today flocking to reflexology spas, where practitioners treat all their problems via the soles of their feet.
The American doctor in question was William H. Fitzgerald, an ear, nose and throat specialist. In a 1917 book, he explained the genesis of his big idea:
Six years ago I accidentally discovered that pressure with a cotton tipped probe on the muco-cutinous margin (where the skin joins the mucous membrane) of the nose gave an anesthetic result as though a cocaine solution had been applied . . . Also, that pressure exerted over any bony eminence of the hands, feet or over the joints, produces the same characteristic results in pain relief . . . This led to my ‘mapping out’ these various areas and their associated connections and also to noting the conditions influenced through them. This science I have named "Zone Therapy."
Chapter titles from Zone Therapy include "Zone Therapy for Women" (tongue depressor into the back of the throat for menstrual cramps), "Painless Childbirth" (rubber bands around the toes, among other interventions) and "Curing Lumbago with a Comb."
A nurse and physical therapist named Eunice D. Ingham extended the idea of zone therapy in the 1930s and 1940s, eventually mapping the entire body onto the soles of the feet. She called each important point on the foot a “reflex” because it reflected back to a certain organ or body part. Ingham wrote two books on the subject, now called reflexology: Stories the Feet Can Tell and Stories the Feet Have Told.
Today, the International Institute of Reflexology describes its practice as as “a science which deals with the principle that there are reflex areas in the feet and hands which correspond to all of the glands, organs and parts of the body.” Stimulating these points “can help many health problems in a natural way.” The site insists, “Reflexology…should not be confused with massage.”
There has been some confusion and blending, though, between Western reflexology and traditional Chinese medicine. Ingham and Fitzgerald's idea of "zones" is similar to the Chinese principle of "meridians." In traditional Chinese medicine, meridians are paths that carry qi through the body and connect the acupuncture points. Reflexology groups like to say that Fitzgerald "rediscovered" the science from more ancient roots. They even claim that ancient Egyptians practiced it, based on tomb paintings showing people holding each other's feet.
Whoever thought it up first, the idea that the soles of your feet hold a miniature map of the entire rest of your body defies a scientific explanation.
“The problem is communication,” says physiologist Steven Swoap. “How does the foot talk to the pancreas?”
The foot is full of sensory nerves, Swoap explains. These can detect temperature, pain or position and send that information to the spinal cord. If the signal is something urgent—say, you stepped on a nail—the spinal cord will send a quick command back to the foot (“STOP!”). If the signal from the foot is a non-painful one (“Hey, I’m walking on grass”), it will travel all the way up the spinal cord to the brain.
“But in no instance do those sensory nerves bypass either the spinal cord or the brain and go directly to the liver, or the kidney, or the colon,” Swoap says. This means your foot can’t communicate directly with any other body part except your spinal cord or brain. Whatever stories the feet have told, they’ve had a limited audience.
Daniel Lynch, a biochemist, points out that sex organs are missing from some reflexology maps. “Why aren’t the gonads on there?” he asks. Other maps label a "testes and ovaries" region around the middle of the heel, but there's variation from one chart to the next.
Setting aside the map itself, Lynch says, “Where is the evidence that it actually works?”
The evidence is slimmer than a stiletto heel. In a 2011 review paper, complementary medicine researchers at the Universities of Exeter and Plymouth dug up every scientific study of reflexology they could find. Out of 23 randomized clinical trials, only 8 “suggested positive effects.”
The quality of the studies was “variable,” the authors write, “but, in most cases, it was poor.” Only four studies that found a positive effect used a placebo control—that is, did massaging the feet without regard to “zones” give patients the same symptom relief? In general, studies tended to use small groups of subjects and not to be replicated by other researchers.
Reflexology has been tested on conditions including asthma, premenstrual syndrome, irritable bowel syndrome, multiple sclerosis, and back pain. If reflexology does have a benefit, “The most promising evidence seems to be in the realm of cancer palliation,” or making patients more comfortable, the authors write. Overall, though, they found no convincing evidence that reflexology has power beyond the placebo.
Not that we should thumb our Q-tip-free noses at the placebo effect. The body has an impressive power to make itself feel better based on our expectations. A foot rub from a professional may very well ease a person’s pain. If that professional says anything about zones, though, it’s only a story.
Image: Foot reflexology chart by Stacy Simone (Wikipedia)
Ernst, E., Posadzki, P., & Lee, M. (2011). Reflexology: An update of a systematic review of randomised clinical trials Maturitas, 68 (2), 116-120 DOI: 10.1016/j.maturitas.2010.10.011
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Ernst, E., Posadzki, P., & Lee, M. (2011) Reflexology: An update of a systematic review of randomised clinical trials. Maturitas, 68(2), 116-120. DOI: 10.1016/j.maturitas.2010.10.011
In archaeology, we are constantly getting updates on old material. When results are released, it isn’t always when the study itself is complete. Further, new methods or techniques may lead to re-analysis of older sites and remains, revealing new conclusions. Updates on old topics can cause increased debate, or end arguments completely depending on the … Continue reading »... Read more »
Geib, P., & Hurst, W. (2013) Should dates trump context? Evaluation of the Cave 7 skeletal assemblage radiocarbon dates. Journal of Archaeological Science, 40(6), 2754-2770. DOI: 10.1016/j.jas.2013.01.034
Coltrain, J., Janetski, J., & Lewis, M. (2012) A re-assessment of Basketmaker II cave 7: massacre site or cemetery context. Journal of Archaeological Science, 39(7), 2220-2230. DOI: 10.1016/j.jas.2012.02.018
Martin, R., Naftel, S., Macfie, S., Jones, K., & Nelson, A. (2013) Pb distribution in bones from the Franklin expedition: synchrotron X-ray fluorescence and laser ablation/mass spectroscopy. Applied Physics A, 111(1), 23-29. DOI: 10.1007/s00339-013-7579-5
What have you seen? It’s a common question in Siem Reap, home to the many hostels and hotels that feed tourists to the Angkor Wat temple complex. Sunburnt tourists trade stories while cooling off in the bar with a can … Continue reading →... Read more »
A mass grave is a burial that includes multiple individuals within one grave. The term is often used for burials with three or more individuals, since burials less than that can be normal burial activity. Usually, the finding of a mass grave means that something specific occurred to cause this, since it is not a … Continue reading »... Read more »
Gowland, R., & Chamberlain, A. T. (2005) Detecting plague : palaeodemographic characterisation of a catastrophic death assemblage. Antiquity, 79(303), 146-157. info:/
Kjellstrom, A. (2005) A sixteenth-century warrior grave from Uppsala, Sweden: the Battle of Good Friday. International Journal of Osteoarchaeology, 15(1), 23-50. DOI: 10.1002/oa.746
The annual meetings of the American Association of Physical Anthropologists were going on all last week, and I gave my first talk before the Association. The talk focused on using resampling methods and the abysmal human fossil record to assess whether human-like brain size growth rates were present in our >1 mya ancestor Homo erectus. This is something I've actually been sitting on for a while, but wanted to wait til the talk to post for all to see. Here's a brief version:Background: Humans' large brains are critical for giving us our unique capabilities such as language and culture. We achieve these large (both absolutely, and relative to our body size) brains by having really high brain growth rates across several years; most notable are exceptionally high, "fetal-like" rates during the first 1-2 years of life. Thus, rapid brain growth shortly after birth is a key aspect of human uniqueness - but how ancient is this strategy?Materials: We can plot brain size at birth in humans and chimpanzees (our closest living relatives) to visualize what makes humans stand out (Figure 1).Figure 1. Brain size (volume) at given ages. Humans=black, chimpanzees=red. Ranges of brain size at birth, and the chronological age of the Mojokerto fossil, in blue.Human data come from Cogueugniot and Hublin (2012), and chimpanzees from Herndon et al. (1999) and Neubauer et al. 2012. The earliest fossil evidence able to address this question comes from Homo erectus. Because of the tight relationship between newborn and adult brain size (DeSilva and Lesnik 2008), we can use adult Homo erectus brain volumes (n=10, mean = 916.5 cm^3) to predict that of the species' newborns: mean = 288.9 cm^3, sd = 17.1). An almost-recent analysis of the Mojokerto Homo erectus infant calvaria suggests a size of 663 cm^3 and an age of 0.5-1.25 years (Coqueugniot et al. 2004; this study actually suggests an oldest age of 1.5 years, but the chimpanzee sample here requires us to limit the study to no more than 1.25 years).Methods: Resampling statistics allow inferences about brain growth rates in this extinct species, incorporating the uncertainty in both brain size at birth, and in the chronological age of the Mojokerto fossil. We thus ask of each species, what growth rates are necessary to grow one of the newborn brain sizes to any infant between 0.5-1.25 years? And from there, we compare these resampled growth rates (or rather, 'pseudo-velocities') between species - is H. erectus more similar to modern humans or chimpanzees? There are 294 unique newborn-infant comparisons for humans and 240 for the chimpanzee sample. We therefore compare these empirical pairs of extant species to 7500 resampled H. erectus newborn-infant pairs, randomly selecting a newborn H. erectus size based on the parameters above, and randomly selecting an age from 0.5-1.25 years for the Mojokerto specimen. This procedure is used to compare both absolute size change (the difference between an infant and a newborn size, in cm^3/year), and and proportional size change (infant/newborn size).Results: Humans' high early brain growth rates after birth are reflected in the 'pseudovelocity curve' (Figure 2). Chimps have a similar pattern of faster rates earlier on, but these are ultimately lower than humans'. Using the Mojokerto infant's brain size (and it's probable ages) and the likely range of H. erectus neonatal brain sizes (mean = 288, sd = 17), it is fairly clear that H. erectus achieved its infant brain size with high, human-like rates in brain volume increase.Figure 2. Brain size growth rates ('pseudo-velocity') at given ages. Humans=black, chimpanzees=red. Ranges of brain size at birth, and Homo erectus, in blue.However, if we look at proportional size change, the factor by which brain size increases from birth to a given age, we see a great deal of overlap, both between age groups within a species, band between different species. Cross-sectional data creates a great deal of overlap in implied proportional size change between ages within a species; it is easier to consider proportional size change between taxa, conflating ages, then (Figure 3). Humans show a massive amount of variation in potential growth rates from birth to 0.5-1.25 years, and chimpanzees also show a great deal of variation, albeit generally lower than in the human sample. Relative growth rates in Homo erectus are intermediate between the two extant species.Figure 3. Proportional brain size increase (infant/newborn size). Significance: Brain size growth shortly after birth is critical for humans' adaptative strategy: growing a large brain requires a lot of energy and parental (especially maternal) investment (Leigh 2004). Plus, in humans this rapid increase may correspond with the creation of innumerable white-matter connections between regions of the brain (Sakai et al. 2012), important for cognition or intelligence. The H. erectus fossil record (1 infant and 10 adults) provides a limited view into this developmental period. However, comparative data on extant animals (e.g. brain sizes from birth to adulthood), coupled with resampling statistics, allow inferences to be made about brain growth rates in H. erectus over 1 million years ago.Assuming the Mojokerto H. erectus infant is accurately aged (Coqueugniot et al. 2004), and that Homo erectus followed the same neonatal-adult scaling relationship as other apes and monkeys (DeSilva and Lesnik 2008), it is likely that H. erectus had human-like rates of absolute brain size growth. Thus, the energetic and parental requirements to raise such brainy babies, seen in modern humans, may have been present in Homo erectus some 1.5 million years ago or so. This may also imply rapid white-matter proliferation (i.e. neural connections) in this species, suggesting an intellectually (i.e. socially or linguistically) stimulating childhood in this species. At the same time, relative brain size growth appears to scale with overall brain size: larger brains require proportionally higher growth rates. This is in line with studies suggesting that in many ways, the human brain is a scaled-up version of other primates (e.g. Herculano-Houzel 2012).This study was made possible with published data, and the free statistical programming language R. Contact me if you want the R code used for this analysis, I'm glad to share it!!!ReferencesCoqueugniot H, Hublin JJ, Veillon F, Houët F, & Jacob T (2004). Early brain growth in Homo erectus and implications for cognitive ability. Nature, 431 (7006), 299-302 PMID: 15372030... Read more »
Coqueugniot H, Hublin JJ, Veillon F, Houët F, & Jacob T. (2004) Early brain growth in Homo erectus and implications for cognitive ability. Nature, 431(7006), 299-302. PMID: 15372030
Coqueugniot H, & Hublin JJ. (2012) Age-related changes of digital endocranial volume during human ontogeny: results from an osteological reference collection. American journal of physical anthropology, 147(2), 312-8. PMID: 22190338
DeSilva JM, & Lesnik JJ. (2008) Brain size at birth throughout human evolution: a new method for estimating neonatal brain size in hominins. Journal of human evolution, 55(6), 1064-74. PMID: 18789811
Herculano-Houzel S. (2012) The remarkable, yet not extraordinary, human brain as a scaled-up primate brain and its associated cost. Proceedings of the National Academy of Sciences of the United States of America, 10661-8. PMID: 22723358
Herndon JG, Tigges J, Anderson DC, Klumpp SA, & McClure HM. (1999) Brain weight throughout the life span of the chimpanzee. The Journal of comparative neurology, 409(4), 567-72. PMID: 10376740
Leigh SR. (2004) Brain growth, life history, and cognition in primate and human evolution. American journal of primatology, 62(3), 139-64. PMID: 15027089
Neubauer, S., Gunz, P., Schwarz, U., Hublin, J., & Boesch, C. (2012) Brief communication: Endocranial volumes in an ontogenetic sample of chimpanzees from the taï forest national park, ivory coast. American Journal of Physical Anthropology, 147(2), 319-325. DOI: 10.1002/ajpa.21641
Sakai T, Matsui M, Mikami A, Malkova L, Hamada Y, Tomonaga M, Suzuki J, Tanaka M, Miyabe-Nishiwaki T, Makishima H.... (2013) Developmental patterns of chimpanzee cerebral tissues provide important clues for understanding the remarkable enlargement of the human brain. Proceedings. Biological sciences / The Royal Society, 280(1753), 20122398. PMID: 23256194
Evolution skeptics argue that some biological structures, like the brain or the eye, are simply too complex for natural selection to explain. Biologists have proposed various ways that so-called ‘irreducibly complex’ structures could emerge incrementally over time, bit by bit. But a new study proposes an alternative route.... Read more »
Robin Ann Smith. (2013) Study proposes alternative way to explain life's complexity. EurekAlert. info:/
A study just published in the Proceedings of the National Academy of Sciences explores the question of penis size and female preference in humans. The study involved making a set of 3D models of human males of various relative body sizes, and fitting them out with various size flaccid penises. These were shown to a…... Read more »
Mautz, B., Wong, B., Peters, R., & Jennions, M. (2013) Penis size interacts with body shape and height to influence male attractiveness. Proceedings of the National Academy of Sciences. DOI: 10.1073/pnas.1219361110
Sea lion is first non-human animal to keep a beat
Ronan is the first known non-human mammal successfully trained to bob
her head in time with a metronome-like sound — and then to apply her new
skill to tempos and music she had not previously heard, according to
researchers at the Long Marine Laboratory at the University of
California, Santa Cruz.
This is the biggest news in auditory (or at least musical) animal behavior, right now. Make sure you get to the bottom of the linked page where you will be rewarded with video evidence. It will be worth your while.
Reminds me of a similar, recent article featuring rhesus macaques. I was quite surprised to find that I had not previously written a post about said article. I won't let it by me a second time.
In this article, the authors describe results which suggest that macaques can detect rhythmic perception, but not beat induction (according to the earlier study, sea lions are the only mammal other than humans that can do both). The theory that there is a distinction between these two faculties is know as the dissociation hypothesis.
None of these terms are intuitively obvious. Beat induction is the ability to detect regularity of beats in a rhythm. It is what gives us our ability to tap our foot along with the beat in a song. Rhythmic perception merely refers to the ability to tell that some specific amount of time has passed. This sort of timing work has been studied extensively in many animal species, and it is well known that pretty much all mammals can time intervals. In fact, I have myself done some work demonstrating rhesus macaques' flexibility in timing intervals (Diapadion et al, unpublished results or something).
There is a major drawback to this monkey study: there is no behavioral data. It is entirely EEG. In many ways, I prefer EEG to fMRI or electrophysiology for brain imaging. EEG takes a distributed look at the activity of billions of neurons, unlike eletrophysiology, where you isolate signals from single neurons and pretend that the entire brain region surrounding acts the same way. fMRI also takes a distributed look at brain activity; in fact it is often more accurate than EEG. Unfortunately you can't put monkey into a MRI scanner unless the monkey has been knocked unconscious. You have to stay still in the scanner to get good data, and monkeys, well, they're not so good at that, ever.
fMRI is also superior to EEG because fMRI allows you to see deep into the brain, whereas EEG only lets you look at surface areas because it is on the surface of the skull that you place the EEG electrodes. There might be something going on deep in the auditory cortices that the authors' EEG findings are missing. Which is why it would be nice to see some results from additional metrics. Practically speaking, I don't believe it is likely that the authors are mistaken; the primate literature supports their hypothesis.
In the sea lion video, the speaker suggests that beat keeping may be far more widespread in the animal kingdom than previously thought. No, probably not. This EEG study suggests that monkeys are totally incapable of beat induction, and it stands to reason (and evidence) that this holds for other primates. As it stands, convergent evolution is the most likely explanation.
Honing, H., Merchant, H., Háden, G., Prado, L., & Bartolo, R. (2012). Rhesus Monkeys (Macaca mulatta) Detect Rhythmic Groups in Music, but Not the Beat PLoS ONE, 7 (12) DOI: 10.1371/journal.pone.0051369... Read more »
Honing, H., Merchant, H., Háden, G., Prado, L., & Bartolo, R. (2012) Rhesus Monkeys (Macaca mulatta) Detect Rhythmic Groups in Music, but Not the Beat. PLoS ONE, 7(12). DOI: 10.1371/journal.pone.0051369
If you watch the tv show Bones, you know that every once in a while Brennan will determine some activity that the deceased did based purely on their skeletal remains. For example, in the Pilot episode she determines that the deceased is a young woman who played tennis. The determination of the activity was based on … Continue reading »... Read more »
Villotte, S., & Knüsel, C. (2013) Understanding Entheseal Changes: Definition and Life Course Changes. International Journal of Osteoarchaeology, 23(2), 135-146. DOI: 10.1002/oa.2289
Cardoso, F., & Henderson, C. (2013) The Categorisation of Occupation in Identified Skeletal Collections: A Source of Bias?. International Journal of Osteoarchaeology, 23(2), 186-196. DOI: 10.1002/oa.2285
Henderson, C., Craps, D., Caffell, A., Millard, A., & Gowland, R. (2013) Occupational Mobility in 19th Century Rural England: The Interpretation of Entheseal Changes. International Journal of Osteoarchaeology, 23(2), 197-210. DOI: 10.1002/oa.2286
Glossolalia – ‘speaking in tongues‘ – is a practice best known in association with ‘Charismatic’ branches of Christianity. Practitioners, often as part of religious services, produce streams of speech which correspond to no known language. But could glossolalia sometimes be associated with a brain abnormality? Here’s an interesting case report: Temporal lobe discharges and glossolalia [...]... Read more »
Last year, there was quite a bit of excitement over a “Genetic Test To Predict Risk for Autism”. The test was revealed in a paper in Molecular Psychiatry, by Australian researchers Skafidas and colleagues. The claim was that a statistical classifier could spot patterns of genetic variation that differed between people with autism and healthy [...]... Read more »
Belgard, T., Jankovic, I., Lowe, J., & Geschwind, D. (2013) Population structure confounds autism genetic classifier. Molecular Psychiatry. DOI: 10.1038/mp.2013.34
Last week I discussed a way of preserving bodies almost indefinitely in some cases: embalming. On the other side of this is decay, the process of bodily decline and biological breakdown of the flesh. If you’ve ever watched any of the forensics crime shows, you know that understanding decay and changes in the body can … Continue reading »... Read more »
Lieverse, A., Weber, A., & Goriunova, O. (2006) Human taphonomy at Khuzhir-Nuge XIV, Siberia: a new method for documenting skeletal condition. Journal of Archaeological Science, 33(8), 1141-1151. DOI: 10.1016/j.jas.2005.12.001
The business and self-help section of my local Kinokuniya bookstore is currently featuring shelves and shelves of Marketplace 3.0: Rewriting the rules of borderless business by Hiroshi Mikitani, the founder and CEO of e-commerce giant Rakuten. I’m not a fan … Continue reading →... Read more »
Gazzola, M., & Grin, F. (2013) Is ELF more effective and fair than translation? An evaluation of the EU's multilingual regime. International Journal of Applied Linguistics, 23(1), 93-107. DOI: 10.1111/ijal.12014
The decisions of this chimpanzee living in the Tchimpounga Chimpanzee Sanctuary are affected by his social situation. Photo by Alex Rosati.If you have a choice between a prize that is awesome half the time and totally lame the other half of the time or a mediocre prize that is a sure-thing, which would you choose? Your choice probably depends on your personality somewhat. It may also depend on your needs and your mood. And it can depend on social contexts, like if you’re competing with someone or if you’re being watched by your boss or someone you have a crush on.All animals have to make choices. Some choices are obvious: Choose the thing that is known to be of high quality over the thing that is known to be of low quality. But usually, the qualities of some options are uncertain and choosing them can be risky. As with us, the likelihood of some primates, birds, and insects to choose riskier options over safer ones can be affected by outside influences. And we aren’t the only species to have our risk-taking choices influenced by social context. Anthropologists Alex Rosati and Brian Hare at Duke University tested two ape species, chimpanzees and bonobos, in their willingness to choose the riskier option in different social situations. They tested chimpanzees living in the Tchimpounga Chimpanzee Sanctuary and bonobos in the Lola ya Bonobo Sanctuary, both in the Democratic Republic of Congo. Most of the apes living in these sanctuaries are confiscated from poachers that captured them from the wild for the pet trade and for bushmeat. In these sanctuaries the animals live in social groups, generally spending their days roaming large tracts of tropical forest and their nights in indoor dormitories. This lifestyle rehabilitates their bodies and minds, resulting in psychologically healthy sanctuary inhabitants.It is in these familiar dormitories that Alex and Brian tested the apes’ propensity for making risky choices. For their experimental set-up, an experimenter sat across a table from an ape and offered them two options: an overturned bowl that always covered a treat that the apes kinda like (peanuts) versus an overturned bowl that covered either an awesome treat (banana or apple) or a lousy treat (cucumber or lettuce). In this paradigm, the peanut-bowl represents the safe choice because whenever the ape chooses it, they know they’re getting peanuts. But the other bowl is the risky choice, because half the time they get fruit (yum!), but the other half of the time they get greens (bummer).This figure from Rosati and Hare's 2012 Animal Behavour paper shows Alex demonstrating the steps they would go through before the ape chose one of the two options.After spending some time training the apes to be sure they understood the game, the researchers tested their choices in different social situations. In each test session, the ape was allowed to choose between the two bowls (and eat the reward) multiple times (each choice was called a trial). But before the test session began and in between choice trials, another experimenter sat with the ape for two minutes and did one of three things: In one group, the experimenter sat at the table and silently looked down (they called this the “neutral condition”). In another group, the experimenter repeatedly offered the ape a large piece of food, pulling it away and grunting whenever the ape reached for it (they called this the “competitive condition”). In a third group, the experimenter tickled and played with the ape (they called this the “play condition”).Alex and Brian found out that whereas bonobos chose the safe option and the risky option about equally, the chimpanzees were significantly more likely to choose the risky option. But despite this species difference, both species chose the risky option more often in the “competitive condition”. Neither species increased their risk-taking in the “play condition”.The graph on the left shows that wheras bonobos chose the safe option and the risky option each about 50% of the time (where the dashed line is), the chimpanzees chose the risky option much more often. The graph on the right shows that both species chose the risky option more often in the "competition condition" than they did in the "neutral condition". Figure from Rosati and Hare's 2012 Animal Behavour paper.These are interesting findings, especially when you consider the natural behaviors and lifestyles of these closely related species. Bonobos can be thought of as the hippies of the ape world, happily sharing and using sex to settle disputes and strengthen relationships. In comparison, chimpanzees are more like gangsters, aggressively fighting over resources and dominance ranks. So in general, the more competitive species is more likely to take risks. But when the social environment becomes more competitive, both species up the ante. This effect doesn’t seem to be simply the result of being in a social situation, because the apes didn’t increase their risk-taking in the presence of a playful experimenter. This still leaves us with some questions to ponder though. Are apes more likely to take risks when an experimenter is offering food and taking it away because of a heightened sense of competition, or is this the result of frustration? And would we see the same effect if the “competitor” were another ape of the same species, rather than a human experimenter? How would their behavior change if they were hungry? These questions are harder to get at, but this research does demonstrate that like in humans, the decision-making process in chimpanzees and bonobos is dependent on social context. Want to know more? Check this out:Rosati, A., & Hare, B. (2012). Decision making across social contexts: competition increases preferences for risk in chimpanzees and bonobos Animal Behaviour, 84 (4), 869-879 DOI: 10.1016/j.anbehav.2012.07.010 ... Read more »
Rosati, A., & Hare, B. (2012) Decision making across social contexts: competition increases preferences for risk in chimpanzees and bonobos. Animal Behaviour, 84(4), 869-879. DOI: 10.1016/j.anbehav.2012.07.010
In modern societies, perfect health and being in-shape are often associated with wealth. Those who have more money have better access to healthier food, ability to hire nutritionists, access to the best gyms and health related centers, and overall tend to be in better health than their poorer counterparts. In the past few years, studies have … Continue reading »... Read more »
Pētersone-Gordina, E., Gerhards, G., & Jakob, T. (2013) Nutrition-related health problems in a wealthy 17–18th century German community in Jelgava, Latvia. International Journal of Paleopathology. DOI: 10.1016/j.ijpp.2013.01.002
Not sure why, but this photo of two young scientists working off Greenland has been in my mind for the last 3 days. It shows a 25-year graduate student of Anthropology from Columbia University, Frederica de Laguna, with one of … Continue reading →... Read more »
VanStone, J., & de Laguna, F. (1980) Voyage to Greenland: A Personal Initiation into Anthropology. Ethnohistory, 27(2), 191. DOI: 10.2307/481234
The Great Basin and northern Colorado Plateau were occupied at the time of European Contact (generally between the late eighteenth and early nineteenth century for this region) by a variety of relatively small groups of hunter-gatherers, all of whom spoke closely related languages belonging to the Uto-Aztecan language family. By the early twentieth century these [...]... Read more »
Bettinger, R., & Baumhoff, M. (1982) The Numic Spread: Great Basin Cultures in Competition. American Antiquity, 47(3), 485. DOI: 10.2307/280231
Kaestle, F., & Smith, D. (2001) Ancient mitochondrial DNA evidence for prehistoric population movement: The numic expansion. American Journal of Physical Anthropology, 115(1), 1-12. DOI: 10.1002/ajpa.1051
Steward, J. (1937) Linguistic Distributions and Political Groups of the Great Basin Shoshoneans. American Anthropologist, 39(4), 625-634. DOI: 10.1525/aa.1937.39.4.02a00070
What is a male? What is a female?
If you were to conduct a survey, most people would probably have little difficulty expressing some fundamental differences. After all, we learn to tell boys apart from girls in early childhood.
Answers in the survey might revolve largely around differences between the sexes in anatomy (including genitalia of course), or might even extend to sex-specific or sex-biased roles in reproduction (which sex gives birth, lactates, is typically the primary carer, and so forth).... Read more »
Paco Garcia-Gonzalez, Damian Dowling, & Magdalena Nystrand. (2013) Male, female – ah, what’s the difference?. The Conversation. info:/
Do you write about peer-reviewed research in your blog? Use ResearchBlogging.org to make it easy for your readers — and others from around the world — to find your serious posts about academic research.
If you don't have a blog, you can still use our site to learn about fascinating developments in cutting-edge research from around the world.
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