Scientists say 'hobbit' was not modern human

Study of the bones in the creature's left wrist lends weight to theory

By Randolph E. Schmid

The Associated Press

Updated: 4:49 p.m. ET Sept. 20, 2007

WASHINGTON - U.S. scientists, wringing their hands over the identity of the famed "hobbit" fossil, have found a new clue in the wrist.

Since the discovery of the bones in Indonesia in 2003, researchers have wrangled over whether the find was an ancient human ancestor or simply a modern human suffering from a genetic disorder.

Now, a study of the bones in the creature's left wrist lends weight to the human ancestor theory, according to a report in Friday's issue of the journal Science.

The wrist bones of the 3-foot-tall (0.91 meter) creature, technically known as Homo floresiensis, are basically indistinguishable from an African ape or early hominin-like wrist and nothing at all like that seen in modern humans and Neanderthals, according to the research team led by Matthew W. Tocheri of the Smithsonian's National Museum of Natural History.

That indicates that it is an early hominin and not a modern human with a physical disorder, they contend.

"It seals the deal," Tocheri said in a telephone interview.

The specimen he studied lived on the Indonesian island of Flores about 18,000 years ago, a time when early modern humans populated Australia and other nearby areas.

Scientists had thought humans had the planet to ourselves since Neanderthals died out about 30,000 years ago, and the discovery of Hobbits indicates another evolutionary cousin who coexisted longer, Tocheri said.

It is not known whether humans and Hobbits coexisted on that island, he said, but it is clear we shared the planet for some time.

"Basically, the wrist evidence tells us that modern humans and Neanderthals share an evolutionary grandparent that the hobbits do not, but all three share an evolutionary great-grandparent. If you think of modern humans and Neanderthals as being first cousins, then the hobbit is more like a second cousin to both," Tocheri said.

When the bones were first discovered some scientists declared them the remains of a new, dwarf species of human ancestors. Because of its tiny stature it was quickly dubbed the "Hobbit," from the creature in the books by J.R.R. Tolkien.

Dean Falk of Florida State University said the new report helps confirm that conclusion.

"This is exciting and should help settle things," she said. "The authors are to be congratulated, not only for describing important new details about 'Hobbit,' but for shedding light on the evolution of the wrist and how it might have related to tool production."

But others have questioned whether it was really a new species. Robert D. Martin of the Field Museum in Chicago and co-authors challenged the original classification, arguing that it appears to be a modern human suffering from microencephaly, a genetic disorder that results in small brain size and other defects.

There are things that can go wrong in the development of the wrist, Tocheri said, but they do not result in a complete change of design from modern human to chimpanzee or gorilla wrist.

Nonetheless, Martin said he is standing by his position.

"My take is that the brain size of (that specimen) is simply too small. That problem remains unanswered," he said in a telephone interview.

"People ask me whether this new evidence changes anything, well it doesn't," he said. "I think the evidence they've presented is fine, it's the interpretation that is problematic."

Copyright 2007 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

URL: http://www.msnbc.msn.com/id/20893732/

Descobert a Dmanisi un nou tipus d’homínid d’1,7 milions d’anys amb un esquelet combinació de trets arcaics i moderns

Font: Bloc IPHES

L’esquelet parcial d’un individu associat a un crani, i les restes postcranials de tres adults, han permès definir com era el cos dels primers homínids que van sortir de l’Àfrica fa 1,7 milions d’anys. Fins ara, es coneixia com podia ser la seva cara, gràcies a uns cranis trobats també a Dmanisi (Geòrgia), atribuïts a Homo georgicus, però finalment s’ha pogut definir també com seria la resta del seu esquelet, gràcies a diferents restes trobades posteriorment en aquest jaciment. L’estudi ha determinat un tipus d’homínid nou, amb combinació de trets antics i moderns, essent en el seu conjunt molt més arcaic del que es pensava, tot i que disposava de capacitat física per recórrer llargues distàncies, amb caràcters heretats de l’Homo habilis.

David Lordkipanidze, director de les excavacions de Dmanisi, amb un húmer del postcranial descobert - Crèdit foto: Georgian National Museum

Aquesta important aportació científica es dóna a conèixer en el volum 449 de la revista Nature del 20 de setembre de 2007. La troballa pertany a un equip internacional dirigit per David Lordkipanidze, director del projecte de recerca de Dmanisi, i entre els signants de l’article hi figuren Bienvenido Martínez-Navarro i Jordi Agustí, com a investigadors ICREA (Institució Catalana de Recerca i Estudis Avançats), IPHES (Institut Català de Paleoecologia Humana i Evolució Social) i URV (Universitat Rovira i Virgili de Tarragona).

Les troballes de postcranial que es presenten a Nature pertanyen principalment a dos individus diferents dels quals ja es coneixien els cranis: el crani 2700, localitzat l’any 2001, corresponent a un jove adolescent, i el D-3.444, aparegut el 2003 i conegut com el vell desdentat, amb la qual cosa hauria de ser alimentat per altres individus, essent la mostra més llunyana que ens ha arribat de comportament altruista. Amb les diferents parts de la resta d’esquelet obtingudes a Dmanisi s’ha pogut comprovar que es tracta d’un nou model homínid, una combinació de trets arcaics heretats d’Homo habilis i Homo ergaster, que després derivaran en Homo erectus asiàtic.

Jordi Agustí, al costat de David Lordkipanidze, en el moment d'extreure el crani D-3.444, trobat el 2003 i conegut com el vell desdentat - Crèdit foto IPHES

Jordi Agustí explica: “es considerava que els primers homínids haurien tingut una morfologia més avançada pel que fa al seu postcranial, en canvi, l’Homo georgicus demostra que, de cames cap avall, té una estructura més moderna, més avançada, però de tòrax cap a munt manté unes característiques físiques arcaiques. Això es concreta en què tenia una bona capacitat per desplaçar-se a peu, però, alhora, l’absència de torsió humeral indica que tenia més flexibilitat per pujar als arbres que espècies més modernes, com l’Homo ergaster, i seria una espècie més adaptada al bosc que a paisatges de sabana”. Les restes postgranials trobades a Dmanisi són d’aquestes parts de l’esquelet: omòplat, clavícula, húmer, vèrtebres, fèmur, tíbia i ossos del peu; no s’ha descobert encara cap pelvis.

Primeres sortides d'Àfrica i sistema locomotor

Sobre les primeres sortides d’homínids d’Àfrica hi ha diversos punts de vista, però, en tot cas, el postcranial de l’Homo georgicus evidencia que “no va ser la possessió d’un sistema locomotor avançat el que va propiciar aquest fet, per la combinació de trets moderns i arcaics exposats –apunta Jordi Agustí-. En tot cas, Dmanisi és l’origen d’Homo erectus, en sentit estricte, ja que ens dóna les claus per entendre l’origen d’aquesta espècie. Si l’Homo antecessor descobert a Atapuerca prové d’Àsia, heretaria també aquesta estructura postcranial, o bé, si aquestes poblacions són producte d’una segona sortida, haurien de tenir una estructura més moderna. De moment, però, no tenim restes postcranials d’aquestes altres espècies per poder-ho comparar”.

Bienvenido Martínez-Navarro, el primer per l'esquerra amb D. Lordkipanidze, al jaciment de Dmanisi

La col·laboració de l’IPHES en el projecte Dmanisi s’emmarca en un conveni establert amb el Museu Nacional de Geòrgia, que dirigeix Lordkipanidze, i amb el qual es va formalitzar una col.laboració institucional que ve de llarg, per la participació de Jordi Agustí i Bienvenido Martínez en el projecte de Dmanisi, implicació que alhora rep el suport de la Generalitat de Catalunya a través del Programa Excava de l’Agència d’Ajuts Universitaris a la Recerca (AGAUR), que pretén esbrinar com es va produir la primera sortida d’Àfrica dels homínids.

En aquest projecte de Dmanisi, “l’aportació nostra –recalca Bienvenido Martínez- s’ha centrat sobretot en l’estudi de la bioestratigrafia (datació del jaciment en funció de les restes de fauna que es localitza en cada nivell geològic) i l’estudi dels macromamífers apareguts”.

Respecte a la fauna de Dmanisi, el mateix investigador ha puntualitzat que és molt variada i presenta elefants de l’espècie Mammuthus meridionalis, girafes primitives, bisons, antílops amb les banyes espiralades, estranys bòvids amb les banyes dirigides cap al davant de l’espècie Soergelia minor, cabres i, sobretot, abundants carnívors, óssos, hienes gegants, tigres de dents de sable de dos tipus (Homotherium i Megantereon ), jaguars, guepards, llops primitius, etc. “Aquesta fauna –assegura Bienvenido Martínez- està d’acord amb una cronologia d’1,7 – 1,8 milions d’anys i ens indica de l’existència en aquella època d’un paisatge variat, amb boscos i zones obertes, molt favorable per a la supervivència dels homínids”. Gran part d’aquesta fauna la trobem també al jaciment d’Orce (Granada).

Dmanisi és un jaciment clau per estudiar la sortida de les primeres poblacions de l’Àfrica, localitzant-se en aquest indret les evidències més antigues d’homínids fora d’aquest continent, amb una antiguitat d’1,7 milions d’anys pertanyents a l’espècie Homo georgicus, possiblement l’espècie pont entre Homo habilis i Homo erectus, en sentit estricte, és a dir, l’homínid que es localitza a Àsia. Tot això reforça el debat sobre el paper del continent asiàtic en els procesos d’evolució de les espècies d’homínides fora d’Àfrica.

Els primers emigrants

• Els habitants del jaciment de Dmanissi, els humans més antics fora de l'Àfrica, tenien cames gràcils i eren baixos

ANTONIO MADRIDEJOS, El Periódico de Catalunya
BARCELONA

Els primers homínids que es van aventurar a deixar el seu bressol africà per colonitzar el món, avançant per climes més durs, van ser uns éssers certament singulars: per una banda, tenien trets anatòmics moderns, com unes proporcions corporals similars a les de l'home actual i unes cames aptes per recórrer grans distàncies; per una altra, mostraven característiques pròpies d'espècies arcaiques com els australopitecs, com la facilitat per enfilar-se, el cervell petit i una estatura inferior al metre i mig. Aquesta és la principal conclusió a què s'ha arribat després de comparar els últims fòssils desenterrats al jaciment de Dmanissi (Geòrgia), molt nombrosos i variats, amb els cranis i la mandíbula presentats anys enrere. Tant els uns com els altres tenen entre 1,8 i 1,7 milions d'anys i són, per tant, les restes d'homínids més antigues que s'han trobat mai fora del continent africà.
Els científics, capitanejats pel paleontòleg local David Lordkipanidze, presenten avui a la revista Nature els últims fòssils trobats a Dmanissi --un cúbit, húmers, costelles, vèrtebres, un fèmur i falanges, entre altres--, que corresponen a tres individus adults i un d'adolescent. Des del 1991, a Geòrgia s'han desenterrat molts ossos i estris de pedra antics, però fins ara no se sabia pràcticament res de l'aparell locomotor.
En el treball han participat tres investigadors espanyols: Bienvenido Martínez-Navarro i Jordi Agustí, de l'Institut de Paleoecologia Humana de Tarragona, i Oriol Oms, de la Universitat Autònoma de Barcelona. Agustí s'ha ocupat de l'anàlisi de la microfauna fòssil, el seu company Martínez-Navarro ha contribuït a l'estudi dels grans mamífers, com els carnívors i els bòvids, i Oms ha estat l'encarregat de precisar la cronologia dels ossos mitjançant estudis estratigràfics i paleomagnètics.
Aquests homínids van haver de passar forçosament pel Pròxim Orient en les seves migracions cap a altres latituds, però mai se n'han trobat restes i possiblement costarà molt trobar-ne. Són els capritxos de la geologia: Geòrgia, en canvi, es va beneficiar d'un paisatge volcànic en canvi constant.

Sabana amb estacions
Dmanissi és un jaciment excepcional situat sota la ciutat medieval del mateix nom, a 85 quilòmetres de la ciutat de Tbilissi. Avui és un paisatge muntanyós d'hiverns rigorosos, però fa 1,8 milions d'anys va acollir possiblement un paisatge de sabana més càlid, encara que amb estacions marcades, explica Martínez- Navarro. "Al costat dels homínids --relata-- hi va haver una fauna variada de rinoceronts, girafes, estruços, antílops, cabruns, bisons, tigres de dent de sabre, somateris..." Els pobladors d'aquella època van ser sobretot recol.lectors i caçadors d'animals petits, encara que probablement no desdenyaven la carronya que deixaven els grans carnívors.
"En general --afirma Martínez- Navarro, que també coordina les investigacions al jaciment d'Orce (Granada)--, els homínids que vivien a Dmanissi tenien una estructura moderna de cintura cap avall i una gran habilitat per caminar grans distàncies, però eren de talla petita". No són exactament com els Homo habilis ni com els posteriors Homo erectus, i han estat batejats com a Homo georgicus. "Són un mosaic", destaca Mar-
tínez, que ha treballat a Geòrgia des del 1997. "Recordo quan només hi havia tres hores d'electricitat, però ara la regió ha millorat molt i es pot visitar com a turista sense cap perill". Aquest jaciment té fins i tot una web pròpia (www.dmanissi.org. ge).

Primates Expect Others To Act Rationally

Science Daily — When trying to understand someone's intentions, non-human primates expect others to act rationally by performing the most appropriate action allowed by the environment, according to a new study by researchers at Harvard University.

Rhesus macaques were one of the three types of primates that responded to an experimenter's actions. (Credit: Photo by Justin Wood)

---

The work was led by Justin Wood, a graduate student in the Department of Psychology in the Faculty of Arts and Sciences at Harvard, with David Glynn, a research assistant, and Marc Hauser, professor of psychology at Harvard, along with Brenda Phillips of Boston University.

"A dominant view has been that non-human primates attend only to what actions 'look like' when trying to understand what others are thinking," says Wood. "In contrast, our research shows that non-human primates infer others' intentions in a much more sophisticated way. They expect other individuals to perform the most rational action that they can, given the environmental obstacles that they face."

The scientists studied the behavioral response of over 120 primates, including cotton-top tamarins, rhesus macaques and chimpanzees. These species represent each of the three major groups of primates: New World monkeys, Old World monkeys and apes. All three species were tested in the same way, and the results showed the same responses among the different types.

In the first experiment, the primates were presented with two potential food containers, and the experimenter either purposefully grasped one of the containers, or flopped their hand onto one of the containers in an accidental manner. For all three species, the primates sought the food container that was purposefully grasped a greater number of times than the container upon which the hand was flopped. This indicates that the primate inferred goal-oriented action on the part of the experimenter when he grasped the container, and was able to understand the difference between the goal-oriented and accidental behavior.

In the second experiment, the researchers asked if the primates infer others' goals under the expectation that other individuals will perform the most rational action allowed by the environmental obstacles. Again, the primates were presented with two potential food containers. In one scenario, an experimenter touched a container with his elbow when his hands were full, and in another scenario, touched a container with his elbow when his hands were empty.

The primates looked for the food in the container indicated with the elbow more often when the experimenter's hands were full. The primates considered, just as a human being would, that if someone's hands are full then it is rational for them to use their elbow to indicate the container with food, whereas if their hands are empty it is not rational for them to use their elbow, because they could have used their unoccupied hand.

Developmental psychologists have long understood that young children are able to engage in this type of rational action perception, but scientists have not understood if this ability is unique to human beings, or shared with other animals. This study suggests that this ability evolved as long as 40 million years ago, with non-human primates.

"This study represents one of the broadest comparative studies of primate cognition, and the significance of the findings is reinforced by the fact that these results were consistent across three different species of primates," says Wood. "The results have significant implications for understanding the evolution of the processes that allow us to make sense of other people's behavior."

The findings appear in the Sept. 7 issue of the journal of Science.

The research was funded by the National Institutes of Health, the Guggenheim, and the National Science Federation.

Note: This story has been adapted from a news release issued by Harvard University.

Avances sobre la inteligencia humana

8/9/2007

Investigación internacional Universidad Complutense de Madrid Una investigación internacional demuestra que la inteligencia humana se debe a una especialización para la cultura. La Universidad Complutense forma parte de este estudio realizado en Alemania con la participación de dos investigadores españoles. Inteligencia humana La investigación sugiere una adaptación biológica específica en el ser humano para la vida social y la cultura, tal como plantea la hipótesis de la inteligencia cultural. Estas habilidades socio-cognitivas especializadas permitirán adquirir otras habilidades cognitivas complejas tanto a través de la imitación como de la educación. El trabajo, que se publicará el próximo viernes en la revista Science, revela una adaptación biológica específica en el ser humano para la vida social y la cultura. Un estudio realizado a lo largo de cuatro años en el Instituto Max Planck de Antropología Evolutiva de Leipzig (Alemania), con participación de la Universidad Complutense, aporta información decisiva sobre las causas de que el ser humano sea “más inteligente” que el resto de los primates. La investigación da la razón a los expertos que mantienen la llamada hipótesis de la inteligencia cultural, según la cual los humanos hemos desarrollado habilidades sociocognitivas especializadas para poder vivir e intercambiar información en grupos culturales y es esta dimensión colectiva, que permite beneficiarse de las habilidades y de los conocimientos de los otros, y que se desarrolla en edades muy tempranas, la que hace al ser humano tan “inteligente”. El estudio descarta la hipótesis de la inteligencia general, que explica la mayor inteligencia por el mayor tamaño cerebral. Desarrollo del estudio El trabajo, que se publicó ayer, en la revista Science, ha sido realizado por cinco investigadores: E. Herrmann, J. Call, M.V. Hernández-Lloreda, B. Hare y M. Tomasello. Dos de ellos son españoles: Joseph Call, del Instituto Max Planck, y María Victoria Hernández-Lloreda, profesora del Departamento de Metodología de las Ciencias del Comportamiento de la Universidad Complutense de Madrid. En la investigación se aplicó una amplia batería de tests cognitivos a 106 chimpancés, 32 orangutanes y 105 niños de 2 años de edad. Si bien niños y grandes simios tuvieron resultados muy similares en lo relativo al conocimiento del mundo físico (tareas espaciales, estimación de cantidades e inferencia causal), en la comprensión del mundo social (imitación, comunicación no verbal o interpretación de intenciones) los niños de 2 años, que aunque ya utilizan el lenguaje aún no están escolarizados, obtuvieron resultados mucho mejores. La investigación sugiere una adaptación biológica específica en el ser humano para la vida social y la cultura, tal como plantea la hipótesis de la inteligencia cultural. Estas habilidades socio-cognitivas especializadas permitirán adquirir otras habilidades cognitivas complejas tanto a través de la imitación como de la educación. La creación de la batería de tests cognitivos que puede ser aplicada tanto a niños como a primates no humanos constituye un logro que va más allá de los resultados específicos de este estudio, ya que abre la vía para poder explorar de forma sistemática las habilidades cognitivas de otras especies de primates, lo que proporcionará el tipo de información necesaria para reconstruir tanto la evolución biológica como cultural de la cognición humana. Este trabajo se enmarca dentro de una colaboración entre el Instituto Max Planck de Antropología Evolutiva de Leipzig (MPI-EVA) y la Universidad Complutense de Madrid (UCM), que comenzó en 2003 y se formalizó con un convenio entre MPI-EVA y el grupo de estudio de las relaciones sociales de la UCM, dirigido por Fernando Colmenares Gil, del que forma parte María Victoria Hernández Lloreda.

Cómo abre un tubo un chimpancé

Un exhaustivo experimento demuestra la habilidad humana del aprendizaje social

JUAN GÓMEZ - Berlín - 07/09/2007, El País

Los primates no humanos no acumulan conocimiento. Los humanos sí, a través del aprendizaje social. Las diferencias entre las habilidades humanas de aprendizaje social y las de los grandes primates se demuestran por primera vez de forma exhaustiva en un estudio del Instituto Max Planck de Antropología Evolutiva que publica hoy la revista Science.

El investigador español Josep Call y su colega Esther Herrmann explicaron ayer en Berlín cómo ocho años de experimentos con unos 230 sujetos -100 niños de dos años y medio, 100 chimpancés y 30 orangutanes- les llevaron a conclusiones que pueden sorprender a los legos en teoría evolutiva y comportamiento animal: el mono improvisa y se enfrenta a los problemas con creatividad -algo roma-, mientras que los niños tienden a remedar los comportamientos que ven.

Un problema típico sería un tubo de plástico que encierra comida. El chimpancé tratará de abrirlo por la fuerza, le dará vueltas, lo morderá y lo golpeará. El niño busca la solución imitando a quien le quede cerca. Si es otro humano que le demuestra la habilidad de abrir el tubo, el niño lo abrirá también por el mismo método. Si está a solas con un mono, lo más probable es que el niño muerda, golpee y trate de abrir el tubo por la fuerza. A los dos años y medio, la aptitud física de los humanos es similar a la de los chimpancés. Sin embargo, los niños superaron correctamente el 74% de las pruebas propuestas por los investigadores cuando éstos les mostraban la solución. Los chimpancés y los orangutanes, sólo el 33%.

El cerebro humano es tres veces mayor que el de los chimpancés. Es una ventaja obvia, que a los investigadores -entre ellos María Victoria Hernández-Lloreda, de la Universidad Complutense de Madrid- no les explica, sin embargo, la mayor inteligencia humana, su capacidad de abstracción y de adaptación. La inteligencia social de la que el hombre dispone ahorra tiempo de aprendizaje y energía. Así, los humanos no tienen que descubrir de nuevo las habilidades que necesitarán en el curso de sus vidas.

Call enarbolaba ayer un sencillo abrebotellas para ilustrarlo. "Ningún ser humano del mundo podría aprender por sí mismo todas las habilidades que se necesitan para fabricar una cosa tan simple como ésta: las aleaciones del metal, las máquinas para la producción, el diseño". Call defiende la hipótesis de que un solo mono, por el contrario, sí que puede aprender por sí mismo todos los comportamientos y habilidades que dominan sus congéneres en la naturaleza. Otro ejemplo al que recurrió Call es el álgebra, que no existió hasta hace poco más de mil años. Su conocimiento se ha extendido a pesar de ello en todo el mundo mediante la enseñanza. Es improbable que pudiera reinventarse por cada generación.

Mantiene el investigador la hipótesis de que los seres humanos desarrollaron estas habilidades por su nomadismo ancestral. Según el científico, "el desarrollo de habilidades sociales facilita el reconocimiento grupal entre individuos aun cuando están rodeados de extraños". Los chimpancés viven en grupos sociales de cierta complejidad y usan signos poco complejos para comunicarse. Sin embargo, apenas abandonan su grupo durante toda su vida, de modo que no necesitan construir frente a extraños su identidad social.

Un niño de dos años es más inteligente que un mono por el entorno cultural

Madrid. (Efe).- Un simio es capaz de hacer pequeñas sumas y de usar herramientas que un niño de dos años no sabe ni cómo coger, pero el pequeño es desde esa edad ya más inteligente por haber aprendido culturalmente a interpretar intenciones y a imitar a los adultos para resolver un problema, no porque tenga un cerebro más grande.

Es decir, la inteligencia humana se debe a una especialización de la cultura, y no a una inteligencia general asociada al mayor tamaño cerebral, según una investigación realizada durante los últimos cuatro años por un equipo internacional en el que han participado los españoles Josep Call y Victoria Hernández-Lloreda. Hernández-Lloreda explicó que para su investigación, que mañana publica la revista Science, se ha aplicado "una amplia batería de tests cognitivos" a 106 chimpancés y 32 orangutanes, y a 105 niños de 2 años de edad.

Para igualar las condiciones de aplicación de los tests a las diferentes especies llegaron a poner una barrera de plexiglás entre quien realizaba las pruebas y el niño, a fin de simular el mismo entorno en el que se hacían a los simios. Los dos obtuvieron resultados muy similares en los tests relativos al conocimiento del mundo que les rodea, e incluso los chimpancés mejor que los niños en operaciones de rotación, sumas de pequeñas cantidades y uso de herramientas.

Sin embargo, los pequeños, lejos aún de la edad de escolarización en la que aprenden a contar y a leer, tuvieron mejores resultados en tareas relacionadas con la comprensión del mundo social. Si los niños simplemente tuvieran más inteligencia general que los grandes simios, se deberían haber encontrado diferencias sistemáticas en todas las áreas, pero no fue así. Las mayores capacidades de los niños en cognición y aprendizaje social a esa edad, cuando aún sus capacidades de cognición física son como las de los grandes simios, sugieren una adaptación biológica específica para la vida social y la cultura.

A partir de esas habilidades están preparados para adquirir otras más complejas y gran cantidad de información a través tanto de la imitación como de la instrucción. Sin esas capacidades socio-cognitivas los niños avanzarían muy poco con respecto a los grandes simios en sus capacidades matemáticas, por ejemplo, ya que no podrían utilizar los símbolos numéricos, explicó Hernández-Lloreda, profesora del departamento de Metodología de Ciencias del Comportamiento de la Universidad Complutense de Madrid (UCM).

Por lo tanto, son las habilidades socio-cognitivas las que dan la clave para entrar en el mundo de la cultura, y crecer dentro de un grupo cultural permite a los niños beneficiarse de las habilidades y el conocimiento adquiridos por el resto de la especie, acceder al uso de herramientas y símbolos, incluido el lenguaje, que otros ya han desarrollado.

El experimento, para el que Hernández-Lloreda elaboró el desarrollo psicométrico de la batería de tests, se realizó en el instituto Max Plank de Antropología Evolutiva de Leipzig (Alemania), donde trabaja Call, que es además codirector del Wolfang Köhler Primate Research Center. El trabajo se enmarca en una colaboración entre el instituto Max Plank y la Universidad Complutense, que comenzó en 2003 y se formalizó con un convenio de colaboración hace dos años entre la institución alemana y el grupo de estudio de las relaciones sociales de la UCM del que forma parte Hernández.

La Vanguardia, 06/09/2007

Fair Testing of Apes

Comment by Frans B. M. de Waal, Ph. D., Director, Living Links, EMORY University


This study claims that apes have equal technical but lower social intelligence than human toddlers. Although it is an impressive battery of tests, and an impressive data analysis, there is a glaring lack of equivalence between the way the children and apes have been tested, one that has been criticized before by others and myself.

It may seem that testing all subjects in the same way is fair and equal, but the children are tested by their own species (a human model), whereas the apes are tested by a stranger of another species (a human model). It is entirely possible that this doesn't make much difference in physical tasks, which after all focus on physical objects, but we do know that it makes a huge difference in relation to social tasks, which by definition focus on the interaction between subject and experimenter.

It is easier to process social information of one's own species. So, it is only seemingly that all subjects were tested in the same way.

Here at the Living Links Center we have in the past five years conducted many tests, which demonstrate that if chimpanzees are tested with their own kind they show impressive social learning. We have specialized in chimp-to-chimp testing precisely to circumvent the confound introduced by the human tester.

Examples can be found on the website of Living Links:
http://www.emory.edu/LIVING_LINKS/diffus.html
http://www.emory.edu/LIVING_LINKS/conform.html

Our results don't fit the "cultural intelligence" hypothesis mentioned in the study, and in fact they contradict the central claim of this new study, because they demonstrate that apes are very good at social tasks. Testing apes with models of their own species takes more time and patience, hence is harder to integrate in a large battery of tests, but it is ecologically more relevant (that is, it relates more closely to the context in which primate cognition evolved, which is of course among members of the same species).

So, unless I see more evidence, my conclusion is that all that this new study demonstrates is how cognitive performance is sensitive to who does the testing: one's own or another species.

Babies and Chimps Compete in Mental Olympics

September 7, 2007, 1:13 pm

By Mike Nizza

Tags: intelligence, wildlife

While The Lede considered Man versus Machine, scientists were studying another historic duel: Baby versus Chimp.

106 chimpanzees, 32 orangutans and 105 humans who were about 2.5 years old were put through “The Primate Cognition Test Battery,” which includes 16 tasks divided between physical and social cognition. Here’s how the authors of the study in the journal Science described the difference:

Physical cognition deals with inanimate objects and their spatial-temporal-causal relations, whereas social cognition deals with other animate beings and their intentional actions, perceptions, and knowledge.

Now brace yourselves, human readers: The babies did not trounce the apes. In fact, chimpanzees scored more correct responses in the tests on causality and just about tied on spatial skills, according to this chart.

But the social learning tests were a rout for the babies, with chimpanzees way behind and orangutans apparently shut out. Reuters outlines how one social learning test went:

A researcher showed the children and apes how to pop open a plastic tube to get food or a toy contained inside. The children observed and imitated the solution. Chimpanzees and orangutans, however, tried to smash open the tube or yank out the contents with their teeth.

Despite the mixed results, Time magazine sounded uplifted. After all, the results suggested that we are special because we “cooperate and share expertise.” And that’s what “has allowed us to build complex societies, collaborate and learn from each other at a high level.”

Why did the monkey pee on his feet?

Published online: 7 September 2007; | doi:10.1038/news070903-18

Study helps to answer question of odd primate behaviour.

Matt Kaplan

Monkey pee: rubbing urine on the hands could be a way of seeking attention. Katalin Laszlo

It may seem strange, but many monkeys wash their hands and feet with urine. Researchers now think they know why.

Since this odd behaviour was first observed, explanatory theories have varied wildly from suggesting that it helps monkeys improve their grip when climbing to saying it is a method of cleaning. One widely supported theory argues that monkeys use urine washing to cool themselves down when temperatures get too high.

But new research hints that it's all about social communication.

The notion of animals using chemical scents to communicate with each other is hardly new. Dogs classically use urine to mark their territory, for example, as do many other creatures. But when it comes to peeing on oneself, researchers had thought physiological reasons might be as important as social ones. It seems they were wrong.

Hot times

Primatologist Kimran Miller and her research colleagues at the National Institutes of Health Animal Center in Poolesville, Maryland, monitored capuchin monkeys for ten months in a captive environment. The researchers would record daily the enclosure temperature and humidity and then note rates of urine washing. Their report, to be published in the American Journal of Primatology, shows that urine washing behaviours did not change with either temperature or humidity.

Instead, Miller and her team noticed a link between urine washing and attention-seeking.

Alpha males, for example, doubled their urine washing rates when being solicited by females. The researchers think this might be how males encourage females to continue paying attention once they've started.

And in 87% of fights or aggressive incidents, the loser of the battle washed in urine. The team suspects that this is also an attention-seeking behaviour — in this case seeking sympathy. But more research is needed to be sure.



"This really challenges the dominant theory that urine washing in capuchins is related to thermoregulation," comments primatologist James Anderson at the University of Stirling in Scotland.

"We see antelope that pee on their throats, vultures that poop on their feet, and monkeys that wash their hands in urine," says behavioural endocrinologist Fred Bercovitch at the centre for Conservation and Research for Endangered Species in San Diego. "It's obvious that urination is about more than elimination and it is great to see research like this that is figuring out why."

Social skills help toddlers outstrip apes in intelligence tests

• Sarah Knapton
• The Guardian
• Friday September 7 2007

Apes may be our closest relatives in the animal world, but in the battle of wits human toddlers are walking tall while their hairy ancestors are still dragging their knuckles.

In a study comparing the abilities of two-year-olds with chimpanzees and orang-utans, children surpassed the apes in social learning skills, researchers found. The findings are likely to lend further credence to the theory that higher social ability is a uniquely human trait, setting us apart from other primates.

Some 105 youngsters and 138 apes were subjected to a battery of cognitive tests over a two-week period during the study. The researchers found that the children were far more advanced than the apes in understanding nonverbal communications, copying solutions to a problem and understanding the intentions of others.

Esther Herrmann, of the Max Planck institute for evolutionary anthropology in Leipzig, Germany, who led the study, said: "This is the first time that anything like this has been done. We compared three species to determine which skills and abilities are distinctively human.

"Social cognition skills are critical for learning. Young human children who had been walking and talking for about one year, but who were still several years away from literacy and formal schooling, far outstripped both chimpanzees and orang-utans on tasks of social cognition."

In one learning test, human children and apes were shown how to pop open a plastic tube to get food or a toy contained inside. While the children watched and imitated the solution, the baffled chimps and orang-utans, tried to smash open the tube or yank out the contents with their teeth.

The toddlers were also better at following an adult's gaze and at pointing towards a cup containing a reward.

Human brains are three times bigger than those of the closest primate relatives. The researchers believe the results could provide crucial insight into cognitive evolution since the human and chimp family trees diverged around 6m years ago. Chimpanzees are considered the closest genetic relatives to humans, with orang-utans slightly more distantly related.

The apes, which performed the tests in animal sanctuaries in Africa and Indonesia, were closer to the toddlers in tests measuring "physical cognitive skills" involving things such as quantities, the researchers reported in the study published in the journal Science.

In the same journal, other researchers said they showed that apes and monkeys possessed skills such as guessing the intentions of others.

They studied cotton-top tamarins, rhesus macaques and chimpanzees.

Tots More Socially Cognitive Than Apes

By LAURAN NEERGAARD

WASHINGTON (AP) — Toddlers may act up like little apes, but researchers who compared the species concluded a 2-year-old child still has the more sophisticated social learning skills.

In one test, preschoolers who wanted a toy hidden in a trick tube intently copied a scientist's movements to retrieve the prize. Chimps watched the lesson, but then mostly tried to smash or bite open the tube. When it came to simple math, however, the apes seemed to know more than the youngsters, apparently "adding" how many tasty raisins researchers had hidden.

In a novel study, scientists lured 106 chimpanzees, 32 orangutans and 105 toddlers to sit through five hours of testing over several days. Researchers were trying to tell which innate abilities are distinctly human.

"Human children are not overall more intelligent than other primates, but instead have specialized skills of social cognition," concluded the lead researcher, Esther Herrmann of Germany's Max Planck Institute for Evolutionary Anthropology. "They learn in a way that chimpanzees don't learn."

But the findings, published in Friday's edition of the journal Science, conflict with other research that suggests the great apes, humans' closest relatives, are quite good at social learning, too. In fact, a second study in the same journal suggests chimps and monkeys have some capacity to infer someone's intentions by their actions. That is pretty complex, human-like thinking.

In that work, the animals sought out food containers that a researcher had grasped purposefully, not just tapped, or a container that he had touched with his elbow when his hands were full, but not one elbowed when his hands were empty.

The chimps and monkeys expected someone to behave rationally and adjusted their own actions accordingly, according to the lead researcher, Justin Wood of Harvard University.

"That shows quite a subtle social understanding going on in these animals," said Dr. Frans de Waal of Emory University's Yerkes National Primate Research Center, a well-known expert in primate cognition who was not involved in the research published Friday.

Comparing innate abilities can shed light on the evolution of human cognition.

Rather than studying one ability at a time, Herrmann and colleagues devised a battery of tests that they administered to 2 1/2-year-old children and to apes in wildlife sanctuaries in Uganda, Congo and Indonesia.

The apes and children fared equally well on tests of how they understood their physical world. Occasionally, apes did better.

For example, chimps and preschoolers could tell at a glance which dish contained a few more raisins. But when the dishes were covered and extra raisins dropped in, the apes kept better track of which dish had more.

Herrmann speculated that perhaps everyone starts out with ape-level math skills that humans surpass upon learning to count.

Then she tested social learning — communication, imitation and gauging intent from behavior. For example, Herrmann hid a treat under one of three cups and pointed to the right one. Preschoolers were much better at knowing to follow her gestures.

Overall, the preschoolers accomplished social-learning tasks correctly 74 percent of the time, while the apes did only 33 percent of the time.

Herrmann concluded that backs one theory of the evolution of human cognition, that specialized social skills more than general intelligence explain why humans learn more, in complex cultural groups, than do other primates.

But to de Waal, the preschoolers just had to imitate another human to pass these tests, while the apes had to imitate a stranger of another species, a higher hurdle.

Herrmann chose orphaned apes raised around humans to minimize those concerns.

Other studies have found that chimps pass similar social-learning tests when they know the human tester well or when a fellow chimp is trained to administer the tests, which is the method Yerkes now uses.

Recall the trick tube that Herrmann's apes could not open right? De Waal trained two chimps from different families to open a trick box in different ways and then sent them home. Later, their relatives mostly opened the box the way their matriarch had been trained, similar to human cultural learning.

Social learning is "maybe not as a perfect as in humans, but it's very well-developed," de Waal said.

Higher social skills are distinctly human, toddler and ape study reveals

Apes bite and try to break a tube to retrieve the food inside while children follow the experimenter's example to get inside the tube to retrieve the prize, showing that even before preschool, toddlers are more sophisticated in their social learning skills than their closest primate relatives, according to a report published in the 7 September issue of the journal Science, published by AAAS, the nonprofit science society.

This innate proficiency allows them to excel in both physical and social skills as they begin school and progress through life.

"We compared three species to determine which abilities and skills are distinctly human," explained Esther Herrmann of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany and lead author of the research paper. Humans differ from their great ape relatives because human brains are about three times the size of the closest primate relatives and humans have language, symbolic math and scientific reasoning.

Esther Herrmann and colleagues compared 105 2-year-old human children, 106 chimpanzees and 32 organutans in a comprehensive battery of physical and social cognitive tests. Click here for more information.

"Social cognition skills are critical for learning," Herrmann said. The children were much better than the apes in understanding nonverbal communications, imitating another's solution to a problem and understanding the intentions of others," she said.

This is the first comprehensive test comparing social and physical skills of children, chimpanzees and orangutans, Herrmann explained, adding that the findings provide important insight into the evolution of human cognition.

The findings support the cultural intelligence hypothesis that suggests that humans have distinctive social cognitive skills to interact in cultural groups, Herrmann said. An alternate hypothesis suggests that humans differ from apes uniformly across physical and social cognitive tasks because they have more general intelligence.

About 230 subjects – chimps, orangutans and 2.5 year-old children – were compared using a battery of tests and found all to be about equal in the physical cognitive skills of space, quantities and causality. In the social skills of communication, social learning and theory-of-mind skills, the children were correct in about 74 percent of the trials, while the two ape species were correct only about 33 percent of the time.

The researchers chose to study children at an age when they have about the same physical skill level of chimpanzees. Children at 2.5 years are old enough to handle these tasks and people have not taught them too much so they provide a good comparison, Herrmann said. The apes ranged in age from 3 to 21.

All of the subjects – about 100 chimps (Pan troglodytes), 100 children (Homo sapiens) and 30 of the more evolutionarily distant orangutans (Pongo pygmaeus) – were given the same cognitive tests that the Max Planck group developed and named the Primate Cognition Test Battery. The battery analyzes primate cognition dealing with the physical and social world (involved in foraging, for example) and was developed based on the primate cognition research of coauthors Josep Call of the Max Planck Institute for Evolutionary Anthropology and Michael Tomasello of the Max Planck Institute for Evolutionary Anthropology.

In one example of the social learning tasks, a researcher demonstrated how to pop open a plastic tube to retrieve food or a toy inside. The children watched and copied. The chimps and orangutans did not imitate the researcher and instead tried to break the tube or pull the contents out with their teeth.

The tests took between three and five hours and were spread between five and eight days over two weeks. The apes were tested in the sanctuaries where they live in Africa and Indonesia.

The researchers plan to test other closely related species with the Primate Cognition Test Battery to map out the evolution of cognitive ability through systematically testing a variety of primate species and eventually comparing their genomes as they become available.

###

"Humans Have Evolved Specialized Skills of Social Cognition: The Cultural Intelligence Hypothesis," by Esther Herrmann, Josep Call, Brian Hare and Michael Tomasello of Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany; María Victoria Hernández-Lloreda at Universidad Complutense de Madrid in Madrid, Spain; and Brian Hare at Duke University in Durham, North Carolina.

The American Association for the Advancement of Science (AAAS) is the world's largest general scientific society, and publisher of the journal Science (www.sciencemag.org). AAAS was founded in 1848, and serves 262 affiliated societies and academies of science, reaching 10 million individuals. Science has the largest paid circulation of any peer-reviewed general science journal in the world, with an estimated total readership of 1 million. The nonprofit AAAS (www.aaas.org) is open to all and fulfills its mission to "advance science and serve society" through initiatives in science policy; international programs; science education; and more. For the latest research news, log onto EurekAlert!, www.eurekalert.org, the premier science-news Web site, a service of AAAS.

Researchers head to Congo to study Bonobo psychology

mongabay.com
5-sep-2007

Researchers have gone to the Democratic Republic of Congo to study the social behavior of bonobos -- a close relative of the chimpanzee -- in the Lola ya Bonobo Sanctuary in Kinshasa.

Vanessa Woods, an author and a participant in the study, will be posting daily updates at her Bonobo Handshake Blog.

"We're always comparing ourselves to chimpanzees, but they're only half the picture," said Woods. "Bonobos and chimpanzees are so opposite in many ways, that we really need to understand bonobos if we're ever going to understand ourselves."

Woods and her colleagues from the Max Planck Institute in Germany will look at cooperation, play behavior and altruistic characteristics in the primates.

Woods and a captive bonobo

"A lot of our experiments look silly, like when I throw a bright red soccer ball back and forth, or wave a red porcupine around. But a lot of these games help us understand the way bonobos think. Are they as obsessed with objects as we are? Are they scared of new things?"

Bonobos are smaller than chimps and live in female-dominated societies. They are widely known for the prominent role that sex plays in conflict resolution.

Because the researchers are studying psychology, they can observe bonobos in the unnatural setting of a 35 hectare forest reserve in Kinshasa.

Similar Influence Found Of Sex And Handedness On Brain In Capuchin Monkeys And Humans

Article Date: 02 Sep 2007 - 16:00 PDT



Capuchin monkeys are playful, inquisitive primates known for their manual dexterity, complex social behavior, and cognitive abilities. New research now shows that just like humans, they display a fundamental sex difference in the organization of the brain, specifically in the corpus callosum, the region that connects the two cerebral lobes.

A recently published paper by Associate Professor of Psychology and Biology Kimberley A. Phillips (Hiram College), Chet C. Sherwood (George Washington University) and Alayna L. Lilak (Hiram College), reports finding both sex and handedness influences on the relative size of the corpus callosum. The researchers' contribution appears in PLoS ONE, the online, open-access journal of the Public Library of Science. The paper can be read at: http://www.plosone.org/doi/pone.0000792.

In the study, thirteen adult capuchins underwent magnetic resonance imaging of the brain to determine the size of their corpus callosum, which is the major white matter tract connecting the left and right cerebral hemispheres. The monkeys were later given a task to determine hand preference. The authors' results led them to conclude that, as in humans, male capuchins have a smaller relative size of the corpus callosum than females, and right-handed individuals have a smaller relative size of the corpus callosum than left-handed individuals.

As the two hemispheres show greater independence of function, the relative size of the corpus callosum is expected to be smaller. This has been documented in humans, and same pattern was found in capuchins. Phillips and her co-authors hypothesize their results are related to hemispheric specialization for complex foraging tasks that require the integration of motor actions and visuospatial information. In the wild, capuchin monkeys utilize both arboreal and terrestrial substrates and are also noted for being very adept at capturing small rapid prey, such as birds, lizards, and squirrels.

While such research frequently is associated with large research universities, Phillips says scientists at small liberal arts colleges such as Hiram often do not receive enough credit and, especially, for involving undergraduates, such as Lilak, in their work.

"It is not where you are," Phillips says. "It is the quality of the science, and scientists at small liberal arts colleges can and do conduct high-quality research. Undergraduates are an integral part of my research team - they participate in lab meetings, brainstorming, sharing ideas. They are colleagues in my lab. They just need a little more mentoring."

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Article adapted by Medical News Today from original press release.
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Disclaimer
The following press release refers to an upcoming article in PLoS ONE. The release has been provided by the article authors and/or their institutions. Any opinions expressed in this are the personal views of the contributors, and do not necessarily represent the views or policies of PLoS. PLoS expressly disclaims any and all warranties and liability in connection with the information found in the release and article and your use of such information.

At Hiram College, Phillips typically has six to eight students working in her laboratory. Alayna Lilak, who received her degree in psychology in May, has recently begun a job as a research technician in a Stanford University lab.

Citation: Phillips KA, Sherwood CC, Lilak AL (2007) Corpus Callosum Morphology in Capuchin Monkeys Is Influenced by Sex and Handedness. PLoS ONE 2(8): e792.doi:10.1371/journal.pone.0000792

Click here for a link to the published article.

Source: Steve Love
Public Library of Science