Anthropology News, Science News

Humans’ ability to easily distinguish among many faces and recognize people they know goes way, way back, say researchers reporting online on June 25th in Current Biology, a Cell Press publication. That assertion stems from new evidence that, like us, rhesus monkeys tell their friends from foes by picking up on the precise layout of facial features.

“We found that monkeys looking at faces perceive an illusion, the Thatcher effect, that humans experience,” said Robert Hampton of Emory University’s Department of Psychology and Yerkes National Primate Research Center. “This powerful perceptual effect shows that face perception depends on detection of the relations among features in a face, not just on detection of the collection of individual features.”

The discovery means that primates have probably perceived faces in essentially the same way for 30 million years or more, he said.

The Thatcher effect refers to the impaired ability to recognize changes in the relations among features in upside-down versus right-side-up faces. (The phenomenon is so named because it was first shown with the image of Margaret Thatcher.) In demonstrating the effect, scientists manipulate the image of a face so that the eyes and mouth are upside down relative to the rest of the face.

“Surprisingly,” Hampton said, “when the image of a face so modified is presented upside down, most people do not think it looks particularly odd. But when viewed right-side up, it looks awful.” It shows that when we look at faces normally, we are especially sensitive to the relations among features. When faces are upside down, however, we process the image more as a collection of features, with less emphasis on their relations to one another.

In the current study, Hampton and his colleagues showed monkeys pictures of monkey faces until they became “bored,” as indicated by a loss of interest in the images. They then showed them digitally manipulated faces, with the eyes and mouth upside down relative to the rest of the face. When the manipulated faces were shown upright, the monkeys took notice and began studying the pictures again. In contrast, upside-down faces held no new interest and the monkeys continued to ignore them as if nothing were amiss.

The findings offer the first demonstration that a non-human primate species shows the Thatcher effect. “This direct evidence of configural face perception in monkeys, collected under testing conditions that closely parallel those used with humans, indicates that perceptual mechanisms for individual recognition have been conserved through primate cognitive evolution,” the researchers said.

Source

Mice carrying a “humanized version” of a gene believed to influence speech and language may not actually talk, but they nonetheless do have a lot to say about our evolutionary past, according to a report in the May 29th issue of the journal Cell, a Cell Press publication.

“In the last decade or so, we’ve come to realize that the mouse is really similar to humans,” said Wolfgang Enard of the Max-Planck Institute for Evolutionary Anthropology. “The genes are essentially the same and they also work similarly.” Because of that, scientists have learned a tremendous amount about the biology of human diseases by studying mice.

“With this study, we get the first glimpse that mice can be used to study not only disease, but also our own history.”

Enard said his team is generally interested in the genomic differences that set humans apart from their primate relatives. One important difference between humans and chimpanzees they have studied are two amino acid substitutions in FOXP2. Those changes became fixed after the human lineage split from chimpanzees and earlier studies have yielded evidence that the gene underwent positive selection. That evolutionary change is thought to reflect selection for some important aspects of speech and language.

“Changes in FOXP2 occurred over the course of human evolution and are the best candidates for genetic changes that might explain why we can speak,” Enard said. “The challenge is to study it functionally.”

For obvious reasons, the genetic studies needed to sort that out can’t be completed in humans or chimpanzees, he said. In the new study, the researchers introduced those substitutions into the FOXP2 gene of mice. They note that the mouse version of the gene is essentially identical to that of chimps, making it a reasonable model for the ancestral human version.

Mice with the human FOXP2 show changes in brain circuits that have previously been linked to human speech, the new research shows. Intriguingly enough, the genetically altered mouse pups also have qualitative differences in ultrasonic vocalizations they use when placed outside the comfort of their mothers’ nests. But, Enard says, not enough is known about mouse communication to read too much yet into what exactly those changes might mean.

Although FoxP2 is active in many other tissues of the body, the altered version did not appear to have other effects on the mice, which appeared to be generally healthy.

Those differences offer a window into the evolution of speech and language capacity in the human brain. They said it will now be important to further explore the mechanistic basis of the gene’s effects and their possible relationship to characteristics that differ between humans and apes.

“Currently, one can only speculate about the role these effects may have played during human evolution,” they wrote. “However, since patients that carry one nonfunctional FOXP2 allele show impairments in the timing and sequencing of orofacial movements, one possibility is that the amino acid substitutions in FOXP2 contributed to an increased fine-tuning of motor control necessary for articulation, i.e., the unique human capacity to learn and coordinate the muscle movements in lungs, larynx, tongue and lips that are necessary for speech. We are confident that concerted studies of mice, humans and other primates will eventually clarify if this is the case.”

First study to look at effect of greenness on inner city children's weight over time

San Diego, October 28, 2008 – Childhood obesity can lead to type 2 diabetes, asthma, hypertension, sleep apnea and emotional distress. Obese children and youth are likely to be obese as adults, experience more cardiovascular disease, high blood pressure and stroke and incur higher healthcare costs. In an article published in the December 2008 issue of the American Journal of Preventive Medicine, researchers report that children living in inner city neighborhoods with higher "greenness" experienced lower weight gains compared to those in areas with less green space.

Researchers from the University of Washington, Indiana University-Purdue University and Indiana University School of Medicine followed more than 3800 children, predominantly African-American and poor, aged 3-16 over a two-year period. Using satellite imaging data to measure vegetation coverage, the investigators found that higher greenness was significantly associated with lower body mass index (BMI) changes in those children. In previous studies of adults, residential density tended to predict physical activity levels, with highly urban environments leading to more walking, less driving and lower BMI. The current study did not find this correlation for children.

Children and youth in urban environments may be active in a wider variety of open spaces (e.g., yards, parks, vacant lots) and less likely to constrain activity to streets and sidewalks. Greenness might indicate proximity to parks, playfields or other open spaces that promote either physical activity or increased time spent outdoors in active play.

Writing in the article, Janice F. Bell, PhD, MPH, Assistant Professor in the department of Health Services at the School of Public Health and Community Medicine, University of Washington, Seattle, and co-investigators state, "This study's findings align with previous research linking exposure to green landscapes with health improvements. Among adults, greenness is associated with less stress and lower BMI, improved self-reported health and shorter post-operative recovery periods. Among children and youth, the positive health effects of green landscapes include improved cognitive functioning and reduced attention deficit hyperactivity disorder symptoms. Ideally, future research in this area will be multidisciplinary – involving city planners, architects, geographers, psychologists and public health researchers – and will consider the ways children live and play in urban environments."

In a commentary published in the same issue of the American Journal of Preventive Medicine, Nick Wareham, MBBS, PhD, of the Institute of Metabolic Science, Cambridge, England, writes, "Previous research on factors associated with physical activity in children has used mostly cross-sectional designs and few prospective studies have been published. In addition, studies have focused mostly on individual biological or psychological factors, with little emphasis, until recently, on collective determinants such as the physical environment. By focusing on environmental determinants in a longitudinal study in children, the study by Bell et al makes an important contribution to the existing literature."

http://www.eurekalert.org/pub_releases/2008-10/ehs-gnm102608.php

Research looks at how intergroup harmony in the US changed as a result of the September 11, 2001, terrorist attacks

Foreign
threats to the United States can encourage tolerance for diversity
domestically and a corresponding intolerance for diversity
internationally, according to a study by University of British Columbia
(UBC) and Stanford University researchers published this week in Journal of Personality and Social Psychology.

On
September 11, 2001, Paul Davies was a post-doctoral fellow at Stanford
University working on the psychology of intergroup relations. As
military jets escorted passenger airliners from the skies in the hours
after terrorist attacks in New York, Washington and in the air over
Pennsylvania, Davies realized that all around him the interactions
between people had shifted dramatically.

"The world changed
instantaneously," he says. "Foreigner became synonymous with enemy.
There was all this animosity directed towards any foreigner, and at the
same time there was an extraordinary outpouring of brotherly love
within America. We had this paradox that 9/11 led to intergroup harmony
inside the United States while leading to intergroup conflict outside
the United States."

Davies decided to look more closely at
what was happening. Within a few months, he and co-investigators Claude
Steele and Hazel Rose Markus from Stanford University had a research
program ready to go — examining the relationship between foreign
threats, national identity and citizens’ endorsement of models for both
foreign and domestic intergroup relations.

"To the best of our
knowledge, this line of research is the first to document these
relationships," says Davies, who is now a professor of psychology at UBC’s Okanagan campus.
"Our initial studies, conducted during the week of the six-month
anniversary of 9/11, had Americans read a U.S. senator’s policy on
intergroup relations. During this period of national challenge,
Americans endorsed multiculturalism more as a domestic policy and
assimilation more as a foreign policy."

Davies notes that a
foreign policy of assimilation presumes that your nation’s values,
principles, and practices are a model for all foreign cultures to
emulate. That’s in stark contrast to multiculturalism, which strives to
have a reciprocal relationship with other cultures and embraces
diversity as a source of strength.

In subsequent research,
American participants were exposed to a United Nations report that
either challenged or supported U.S. global status. Americans who read
that foreigners were threatening the dominant status of the U.S. once
again revealed a strong preference for assimilation (i.e. promoting the
U.S. as a model for foreign countries to emulate) as a foreign policy,
but Americans who read that foreigners were supporting the dominant
status of the U.S. no longer revealed this preference.

"Most
recently, we discovered that Americans primed with 9/11 — a foreign
threat — revealed higher levels of national identity than those primed
with the Columbine massacre — a domestic threat," says Davies. He
points out that a heightened level of national identity predicted
support for multiculturalism as a domestic policy and support for
assimilation as a foreign policy.

"During a period of national
challenge, embracing one’s national identity can be highly adaptive,"
Davies says. "The healing power of embracing one’s national identity
was obvious among the 78 percent of Americans who indicated, in 2002,
that 9/11 and its aftermath has changed America for the better. Perhaps
the greatest tragedy of all is that calamity can unite people in a way
that shared humanity cannot."

Source University of British Columbia

A study reported in the August 8th issue of the journal Cell,
a Cell Press publication, reveals the complete mitochondrial genome of
a 38,000-year-old Neandertal. The findings open a window into the
Neandertals’ past and helps answer lingering questions about our
relationship to them.

" For the first time, we’ve built a
sequence from ancient DNA that is essentially without error," said
Richard Green of Max-Planck Institute for Evolutionary Anthropology in
Germany.

The key is that they sequenced the Neandertal
mitochondria—powerhouses of the cell with their own DNA including 13
protein-coding genes—nearly 35 times over. That impressive coverage
allowed them to sort out those differences between the Neandertal and
human genomes resulting from damage to the degraded DNA extracted from
ancient bone versus true evolutionary changes.

Although it is
well established that Neandertals are the hominid form most closely
related to present-day humans, their exact relationship to us remains
uncertain, according to the researchers. The notion that Neandertals
and humans may have "mixed" is still a matter of some controversy.

Analysis of the new sequence confirms that the mitochondria of
Neandertal’s falls outside the variation found in humans today,
offering no evidence of admixture between the two lineages although it
remains a possibility. It also shows that the last common ancestor of
Neandertals and humans lived about 660,000 years ago, give or take
140,000 years.

Of the 13 proteins encoded in the
mitochondrial DNA, they found that one, known as subunit 2 of
cytochrome c oxidase of the mitochondrial electron transport chain or
COX2, had experienced a surprising number of amino acid substitutions
in humans since the separation from Neandertals. While the finding is
intriguing, Green said, it’s not yet clear what it means.

" We
also wanted to know about the history of the Neandertal’s themselves,"
said Jeffrey Good, also of the Max-Planck Institute. For instance, the
new sequence information revealed that the Neandertal’s have fewer
evolutionary changes overall, but a greater number that alter the amino
acid building blocks of proteins. One straightforward interpretation of
that finding is that the Neandertal’s had a smaller population size
than humans do, which makes natural selection less effective in
removing mutations.

That notion is consistent with arguments
made by other scientists based upon the geological record, said
co-author Johannes Krause. "Most argue there were a few thousand
Neandertals that roamed over Europe 40,000 years ago." That smaller
population might have been the result of the smaller size of Europe
compared to Africa. The Neandertals also would have had to deal with
repeated glaciations, he noted.

" It’s still an open question
for the future whether this small group of Neandertals was a general
feature, or was this caused by some bottleneck in their population size
that happened late in the game?" Green said. Ultimately, they hope to
get DNA sequence information for Neandertals that predated the Ice Age,
to look for a signature that their populations had been larger in the
past.

Technically, the Neandertal mitochondrial genome
presented in the new study is a useful forerunner for the sequencing of
the complete Neandertal nuclear genome, the researchers said, a feat
that their team already has well underway.

Obesity linked to newer, less walkable neighborhoods

SALT LAKE CITY – The age of your neighborhood may influence your risk
of obesity, according to a new study from the University of Utah.

        The study, to be published in the September issue of the American Journal of Preventive Medicine,
linked the body mass index (BMI) of nearly a half million Salt Lake
County residents to 2000 Census data. The study found that residents
were at less risk of being obese or overweight if they lived in
walkable neighborhoods—those that are more densely populated, designed
to be more friendly to pedestrians and have a range of destinations for
pedestrians.

The study found that neighborhoods built before
1950 tended to offer greater overall walkability as they more often
were designed with the pedestrian in mind, while newer neighborhoods
often were designed to facilitate car travel.

Demographer Ken
Smith, co-author of the study and professor of family and consumer
studies at the University of Utah, says that although individuals
clearly make personal decisions that influence their weight,
neighborhood characteristics also play a potentially important role in
affecting residents’ risk of obesity.

"It is difficult for
individuals to change their behavior," he says, "but we can build
environments that promote healthy behavior."

Using height and
weight data collected by the Driver License Division of the Utah
Department of Public Safety, Smith and colleagues calculated the BMI of
453,927 Salt Lake County residents age 25 to 64, linking it to
census-block groups via geographical coordinates. To protect
confidentiality, all personal information from the Driver License
Division was removed before the data were provided to the researchers.
The study was approved by the University of Utah Institutional Review
Board.

The study found that a man of average height and
weight (6 feet, 200 pounds) weighed 10 pounds less if he lived in a
walkable neighborhood versus a less walkable neighborhood. A woman of
average size (about 5-foot-5, 149 pounds), weighed six pounds less.

        "The data show that how and where we live can greatly affect our health," says Smith.

According to the study, during 2003-2004 roughly 70 percent of men and
61 percent of women in the U.S. were overweight. The study also notes
that by 2030, about half the buildings in the U.S. will have been built
since 2000. How this growth occurs will have a significant impact on
the environment and on the health of the people living in it, Smith
says.

"We have the opportunity, using evidence-based data on
community design, to create neighborhoods that encourage less car
driving, benefiting residents’ health and wallets and shrinking our own
carbon footprint," says Smith.

Neighborhoods with higher
percentages of pedestrian traffic—something the study found is
associated with less obesity among residents—can serve as models for
future residential development and redevelopment. "Neighborhoods with
higher fractions of residents that walk to work tell us that something
beneficial about the neighborhood is promoting health," notes Smith.

"We expect these results mean that residents find walking more
attractive and enjoyable where there are other walkers, a variety of
destinations easily accessible by foot and pedestrian-friendly street
networks. People want to walk when it’s pleasant, convenient and when
there is a destination."

Taunya Dressler – University of Utah

One of the easiest ways to identify an object is by its color –
perhaps it is because children’s books encourage us to pair certain
objects with their respective colors. Why else would so many of us
automatically assume carrots are orange, grass is green and apples are
red?

In two experiments by Holger Mitterer and Jan Peter
de Ruiter from the Max Planck Institute for Psycholinguistics,
perception of color and color constancy (the ability to see the same
color under varying light conditions) were examined using different
hues of orange and yellow. By using these hues on different objects,
the researchers hoped to show that knowledge of objects can be used to
identify color.

In one experiment, half of the
participants saw traditionally-colored orange objects in their
respective hue, while the other participants saw the same objects in an
ambiguous hue between yellow and orange. The participants that saw the
ambiguous hue on traditionally-colored orange objects later called the
item with that ambiguous hue "orange". Apparently, seeing the ambiguous
hue on a traditionally-colored orange objects led participants to
redefine that hue to be proper "orange".

In the second
experiment, participants saw the same hues, but now on objects that
could be any color (e.g., a car). Some participants were shown objects
that ranged from the ambiguous color from the first experiment to a
strong yellow hue, while others were shown objects in a range of strong
orange hues to the ambiguous color. Just as in the first experiment,
participants then had to identify a sock that had been colored with an
ambiguous hue. This second experiment revealed no differences between
the two groups, showing conclusively that it was only the knowledge of
how objects are naturally colored that made them redefine the colors in
the first experiment.

The results, published in the July issue of Psychological Science,
a journal of the Association for Psychological Science, determined that
the use of top-down processing, such as a carrot signifying the color
orange, is delayed in both color perception and also in other
perceptual domains. If humans used this conceptual knowledge
immediately, it would override perceptual cues and cause
hallucinations.

“Delayed feedback for learning prevents
such illusions, but still utilizes prior probabilities provided by
world knowledge to achieve perceptual constancy,” the researchers
concluded.

Author  Contact: Holger Mitterer Holger.Mitterer@mpi.nl

New data may help doctors more accurately diagnose patients

The
expectation that East-Asian people emphasize physical symptoms of
depression (e.g. headaches, poor appetite or aches/pains in the body)
is widely acknowledged, yet the few available empirical studies report
mixed data on this issue. A new study from the Centre for Addiction and
Mental Health (CAMH) debunks this cultural myth, and offers clinicians
valuable insight to into cultural context when assessing a patient,
leading to more accurate diagnosis.

Lead by CAMH Clinical
Research Director Dr. R. Michael Bagby, in collaboration with Dr.
Andrew Ryder, Concordia University, Steven Heine, University of British
Columbia and a number of collaborators from Second Xiangya Hospital of
Central South University, People’s Republic of China, this study
recruited more than 200 participants, half from an outpatient clinic in
China, and half from a clinical research department outpatient clinic
at CAMH, and tested two central hypotheses: 1. East-Asian participants
will emphasize somatic or physical symptoms of depression more than
North American participants, and 2. North American participants would
emphasize psychological symptoms of depression (e.g. report feeling
sad, crying spells, or a loss of self-confidence) more than East-Asian
participants. Dr. Bagby and his team also wanted to examine the role
stigma and alexithymia (difficulty using words to describe emotions)
play in how each culture presented and expressed depression symptoms.

This
rigorous work is one of only a few studies to address these questions
with a direct cross-cultural comparison of clinical patients. Also, it
is the only study to use three assessment tools (spontaneous report of
problems during unstructured discussion with doctor; clinician-rated
symptoms in a structured clinical interview; and a symptom rating scale
in questionnaire form) translated into both English and Chinese
(Mandarin) and modified to address cross-cultural differences.

As
Dr. Bagby explains, "the onset of depression triggers a biological
response that takes place within a specific social context, resulting
in a cascade of somatic and psychological experiences that are
interpreted through a particular cultural lens. Careful translation and
adaptation of our assessment tools helped us clarify if different
approaches lead to different symptom profiles and conclusions about
patients."

Overall, the data demonstrate a consistently
greater level of psychological symptom reporting in the North American
sample, regardless of assessment tool. This suggests a tendency for
Western cultures to emphasize psychological symptoms of depression
(psychologization), rather than a tendency for those from East-Asian
cultures to emphasize physical symptoms (somatization).

East-Asian
participants did report a significantly higher level of somatic
symptoms when reporting through the spontaneous interview and
structured clinical interview. Also, these participants reported higher
levels of stigma and alexithymia. A refined examination of this link
revealed that the observed cross-cultural differences in somatic
symptom scores relates, in part, to cultural differences in internally
versus externally oriented thinking. This suggests that people who do
not frequently focus on their internal emotional state are more likely
to notice somatic symptoms.

While this data may help
clinicians be more aware of how culture can impact how people talk
about their illness, this data does not constitute a norm for
depression worldwide. More work should be done to understand the
interaction of biology, culture and individual differences in
predicting variations in how people present symptoms of depression.

With thanks to the Centre for Addiction and Mental Health

Amazonian tribe has no word to express ‘one,’ other numbers

An Amazonian language with only 300 speakers has no word to express
the concept of "one" or any other
specific number, according to a new
study from an MIT-led team.

The team, led by MIT professor of
brain and cognitive sciences Edward Gibson, found that members of the
Piraha tribe in remote northwestern Brazil use language to express
relative quantities such as "some" and "more," but not precise numbers.

It
is often assumed that counting is an innate part of human cognition,
said Gibson, "but here is a group that does not count. They could
learn, but it’s not useful in their culture, so they’ve never picked it
up."

The study, which appeared in the June 10 online edition of
the journal Cognition, offers evidence that number words are a concept
invented by human cultures as they are needed, and not an inherent part
of language, Gibson said.

The work builds on a study published in
2004, which found that the Piraha had words to express the quantities
"one," "two," and "many." The MIT researchers observed the same
phenomenon when they asked Piraha speakers to describe sets of objects
as they were added, from one to 10.

However, the MIT team decided
to add a new twist–they started with 10 objects and asked the tribe
members to count down. In that experiment, the tribe members used the
word previously thought to mean "two" when as many as five or six
objects were present, and they used the word for "one" for any quantity
between one and four.

This indicates that "these aren’t counting numbers at all," said Gibson. "They’re signifying relative quantities."

He
said this type of counting strategy has never been observed before,
although it may also be found in other languages believed to have
"one," "two," and "many" counting words.

The paper is part of a
larger project that investigates the relationship between Piraha
culture and their cognition and language, testing some claims by Daniel
Everett, a linguist at Illinois State University, in a 2005 issue of
Current Anthropology.

One other discovery of the project is
that the Piraha can perform exact matching tasks as long as there is no
memory component to them, but once there is a memory component, they
approximate their matches. This suggests that language is a cognitive
technology that aids humans in memory tasks.

Lead author of the
paper is Michael Frank, a graduate student in Gibson’s lab. Other
authors are Evelina Fedorenko, a postdoctoral associate at the McGovern
Institute for Brain Research at MIT, and Everett.

massachusetts institute of technology

While the act of selecting an everyday writing utensil seems to be a
simple enough task, scientists have found that it actually could shed
light on complex cultural differences.    

Psychologists
Toshio Yamagishi, Hirofumi Hashimoto and Joanna Schug from Hokkaido
University in Sapporo, Japan used the seemingly simple task of pen
choice to determine if Japanese and American cultural differences are a
function of social constraints. According to the scientists, previous
psychological research on the topic has been flawed since it tends to
attribute an individual’s culture-specific behavior to their inherent
preferences.    

“In this perspective, preferences are the
dominant determinants of behavior only in a social vacuum where
individuals do not need to consider the reactions of others,” wrote the
authors in the June 2008 issue of Psychological Science, a
publication of the Association for Psychological Science. “And we
believe cultural psychologists would agree that culture-specific
behavior does not occur in a social vacuum.”    

The
psychologists hypothesized instead that individuals may be maintaining
culture-specific behaviors by repeatedly relying on proven social
strategies. For example, what appears to be a person’s preference for
conformity in Japanese culture alternatively might be an individual’s
avoidance of a social stigma.    

To support this theory, the
scientists arranged a series of studies designed to disprove, or at
least argue against, the widely accepted stereotype that Americans
prefer qualities of uniqueness while the Japanese intuitively value
conformity. American and Japanese participants were presented with
various scenarios that asked them to select, actually and
hypothetically, a pen from a cup filled with four pens of one color and
one pen of another, alternating between green and orange. The results
show that both American and Japanese participants were more likely to
select a majority pen over the uniquely-colored pen if they had been
previously monitored by other participants or asked to choose with an
experimenter present.    

The results also revealed that the
American and Japanese participants reacted similarly in situations that
had a clearly defined impact on others — as was the case with
purchasing a pen, which obviously did not affect anyone else. And only
the scenarios in which the social relevance was ambiguous, such as
hypothetically selecting a pen to take a survey, did Japanese
participants choose the majority, and Americans the unique, pens. The
findings not only suggest that innate cultural differences were not the
deciding factor, but that the default reaction for pen choice may be
strongly correlated with differences in social constraints.    

As
Yamagishi explained, “What is typically interpreted as differences in
the ‘preference’ for uniqueness and conformity among Japanese and
Americans is actually a reflection of how people interpret ambiguous
situations. By default, Japanese tend to view situations as ones in
which they are under surveillance from others, whereas Americans tend
to view the same situations as ones in which no one cares about their
choices.”

Author Website