Replicated Hauser Results

Some of you may remember last summer Marc Hauser was found guilty of research misconduct. This investigation raised questions about several publications including a paper from 2007 in Science. This paper looked into the ability of non-human primates to understand the intentions of a human experimenter by interpreting his gestures.

Today Science has published a partial replication of the study in question which confirms the original findings that chimpanzees, cotton-top tamarins, and rhesus macaques can distinguish intentional gestures, such as pointing to indicate a container with food inside, from “accidental” actions such as a hand flopping against a container.

The Science wesite states the following:

Following the Harvard misconduct investigation, first author Justin Wood, now an assistant professor at the University of Southern California in Los Angeles, wrote to Science in June 2010 to notify the journal that the investigation had revealed that the original field notes for the rhesus experiments could not be found:

“An internal examination at Harvard University determined that there are no field notes, records of aborted trials, or subject identifying information associated with the rhesus monkey experiments; however, the research notes and videotapes for the tamarin and chimpanzee experiments were accounted for. Professor Hauser states that “most of the rhesus monkey observations were hand written by [co-author David D.] Glynn on a piece of paper, and then the daily results tallied and reported to Wood over email or by phone” and then the raw data were discarded. The research assistant who performed the experiments (Glynn) confirmed that these field notes were discarded.”

Hauser and Wood returned to Cayo Santiago island in Puerto Rico to redo the experiments from the 2007 paper with the same population of free-ranging rhesus monkeys. Their findings, including field notes and video trials, are available online and they essentially match those reported in the original paper.

It is still not known what went wrong with the original experiment, a statement issued by Science today only says the following:

We stress that this new publication aims only to determine whether the original rhesus monkey experiments from the 2007 paper can be replicated. It has no bearing on questions raised about Dr. Hauser’s larger body of work.

This article from Science Inside quotes Dario Maestriperi as saying:

“The results of this replication are straightforward and entirely consistent with those of the original study. If the authors’ interpretation of their results is correct, these findings are very important and represent one of the clearest demonstrations that nonhuman primates can interpret the behavior of other individuals as intentional or non-intentional….Since the experimenter who tested the rhesus monkeys in the replication study appeared from the video to be the first author on the paper, Justin Wood, he was clearly knowledgeable of the hypotheses being tested and had some strong expectations and desires about the monkeys’ performance on the test.”

So is this replication a clarification of groundbreaking findings or could the monkey’s behaviour be down to the Clever Hans effect?

Meanwhile investigations into Hauser’s research are still ongoing and he is still banned from teaching for the next academic year.


The path to empathy

Published online at Plos one yesterday a study done at the Yerkes National Primate Research Center by Campbell and de Waal (2011) has found a link between social groups and empathy in chimpanzees as demonstrated by involuntary yawning responses.

The study is based on the psychological concept of ingroups and outgroups. In humans ingroups are those we see as similar to ourselves and outgroups are those we perceive as different.

Biases involved in ingroup-outgroup discrimination in know to even extend to involuntary responses which includes empathy for pain. This has never been tested in other animals though.

Contagious yawning is thought to be linked with empathy. The study used this assumption to test if chimpanzees’ ingroup-outgroup biases would effect how contagious a yawn can be. In other words if contagious yawning is linking to empathy and empathy is linked to ingroup-outgroup biases within chimpanzees then the chimpanzees should yawn more in response to watching ingroup members yawn than outgroup.

The study used 23 chimpanzees from two separate groups and they were made to watch videos of familiar and unfamiliar individuals yawning. Videos of the same chimps not yawning were also used for control. The chimpanzees yawned more when watching the familiar yawns than the familiar control or the unfamiliar yawns, demonstrating an ingroup-outgroup bias in contagious yawning.

The authors have suggested that these result may be more magnified in chimpanzees than it is in humans as chimpanzees live in much smaller communities than humans and are generally very hostile to those outside of their small social group. Ingroup-outgroup biases are therefore probably much more absolute in chimpanzees.

This study adds empirical evidence to suggest that contagious yawning is subject to empathy. This may have further implications for studying the evolutionary foundations of empathy which obviously has implications for things like theory of mind which is pretty high up on the list for preadaptations for language.


Campbell MW, de Waal FBM (2011) Ingroup-Outgroup Bias in Contagious Yawning by Chimpanzees Supports Link to Empathy. PLoS ONE 6(4): e18283. doi:10.1371/journal.pone.0018283

Project Nim

How cool is this? They’ve made a movie about Nim Chimpsky called Project Nim!

By the same guys who made Man on Wire, it’s currently been shown at the Sundance Festival.

Nim was  raised and nurtured like a human child in order to see to what extent apes could acquire human language.


Following Nim’s extraordinary journey through human society, and the enduring impact he makes on the people he meets along the way, the film is an unflinching and unsentimental biography of an animal we tried to make human. What we learn about his true nature – and indeed our own – is comic, revealing and profoundly unsettling.

Imitation and Social Cognition in Humans and Chimpanzees (II): Rational Imitation in Human Infants and Human-Raised Chimps

In my last post I wrote about two experiments on imitation in young children and chimpanzees by Lyons et al. (2005) and Horner & Whiten (2005).  Their results suggested that young children tend to copy both the ‘necessary’ and the ‘unnecessary’ parts of a demonstrator’s action who shows them how to get a reward out of a puzzle box, whereas chimps only copy the ones necessary to get the reward.

ResearchBlogging.orgOne important question raised by these experiments was whether these results can only be applied to wild chimpanzees or whether they also hold for enculturated, human-raised chimps. This is an important question because it is possible that chimpanzees raised in these kinds of richly interactive contexts show more sensitivity to human intentionality.

Buttelman et al. (2007) tested just that. They used the “rational imitation” paradigm, which features two conditions

a) the subjects are shown an action in which the specific manner of the action is not purposive and intentional but results from the demonstrator being occupied with something else. For example, he may be carrying something so that he has to use his foot to turn on a light (often called the Hands Occupied Condition).

b) the subjects are shown an action in which the demonstrator chooses a specific manner of doing something on purpose. For example he may have his hands free but still choosto turn on the light with his foot (Hands Free Condition).

taken from Call & Tomasello 2008

Continue reading “Imitation and Social Cognition in Humans and Chimpanzees (II): Rational Imitation in Human Infants and Human-Raised Chimps”

What Makes Humans Unique ?(IV): Shared Intentionality – The Foundation of Human Uniqueness?

What Makes Humans Unique (IV): Shared Intentionality – The Foundation of Human Uniqueness?

Shared or collective intentionality is the ability and motivation to engage with others in collaborative, co-operative activities with joint goals and intentions. (Tomasello et al. 2005). The term also implies that the collaborators’ psychological processes are jointly directed at something and take place within a joint attentional frame (Hurford 2007: 320, Tomasello et al. 2005).

Michael Tomasello and his colleagues at the Max-Planck-Institute for Evolutionary Anthropology in Leipzig, Germany have proposed that shared intentionality and the cognitive infrastructure supporting it may be the crucial feature that makes humans unique.

(You can hear Michael Tomasello talk about shared intentionality in his brief 2009 acceptance speech for the prestigeous “Hegel-Price” here. Transcript here)

Continue reading “What Makes Humans Unique ?(IV): Shared Intentionality – The Foundation of Human Uniqueness?”

Some Links #4

Back to the future on syntax and Broca’s area. Talking Brains provide a concise and humorous post about why Broca’s area is not the seat of syntax, be it domain-specific or domain-general. I tend to think that areas important for syntactic processing are probably distributed throughout the left perisylvian region. Hence why Broca’s aphasiacs are quite capable of making grammatical judgements. Then again, another reason why damage to Broca’s area doesn’t, to quote Hickok, “obliterate the ability to make such judgements”, is because the processing shifts to another region (sort of an ancillary system). This is very possible in the advent of neuroplasticity.

Neuroplasticity is a dirty word. Having mentioned neuroplasticity, I now feel obligated to mention this brilliant post over at Mind Hacks. It provides a sort of 101 approach to neuroplasticity, which, after all, simply means something in the brain has changed. Still, as one poster from pointed out: “However, at its most abstract, the concept of neuroplasticity is often arrayed against that other commonplace abstract notion, that the brain is genetically ‘hard-wired’ in some way”.

Dialect Geography and Social Networks. Mark Lieberman over at Language Log discusses geographical patterns of linguistic variation and recent analyses of facebook networks in the US. Put succinctly: they don’t line up very well. He also asks some interesting questions about the role facebook might play as a proxy for communication patterns.

How best to learn R. R is an invaluable statistical package. If, like me, you find yourself being dropped in at the deep end, then things can seem slightly confusing in an environment that is far less user friendly than, say, SPSS. All the important stuff is in the comments section of the post, but you should take some time out to have a general poke around Statistical Modelling, Causal Inference and Social Science.

Are Scottish People Living Dangerously? The short answer: Yes. Barking Up The Wrong Tree links to a study claiming that “Almost the entire adult population of Scotland (97.5%) are likely to be either cigarette smokers, heavy drinkers, physically inactive, overweight or have a poor diet.”

The Sun Gone Crazy? Apparently, for the past two years there’s been a prolonged absence in sunspots. But as Adam Frank mentions, “The magnetic activity of stars like sun, which is the root cause of the sunspot cycle, is still poorly understood even after decades of intense study.  It’s more than an academic concern”.

Three Questions for Michael Tomasello. A cool little interview with the chimpanzee, linguistic and cooperation guru, Michael Tomasello, over at cognition and culture.

Some links #3

Of my random meanderings around the Internet, I think the coolest thing I’ve seen this past week certainly has to be the Steampunk sequencer:

With that out of the way, here are some links:

Schizophrenia and brain evolution (plus bold adjectives) When exploring the etiology of schizophrenia, a feat that has mostly eluded understanding for over 100 years, a common denominator emerges in that associated deficiencies are rooted in cognitively demanding tasks. One suggestion is that, where schizophrenic individuals are involved, disorganised thoughts, abnormal speech, auditory hallucinations and paranoid delusions are symptomatic consequences of our haphazardly evolved brains. It might not seem revelatory, nor is it a particularly new thought on the matter, yet this disorder clearly has ties with human-specific, recently evolved behaviours, such as language and social relationships. And it is here in which our problem emerges: we don’t even know how language or social relationships evolved. In fact, the evolution of the human brain is still very much an enigma, despite the whole host of literature having you believe otherwise. As Darwin put it: “Ignorance more frequently begets confidence than does knowledge[…]”.

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