Science – Page 10 – Replicated Typo

Social networks and Cooperation

A new paper in Nature, by Apicella, Marlowe, Fowler & Christakis was published today. It hypothesises that social network structure may have been present in early human history, and this structure may account for the emergence of cooperation.

A new paper in Nature, by Apicella, Marlowe, Fowler & Christakis, was published today. It hypothesises that social network structure may have been present in early human history, and this structure may account for the emergence of cooperation. The study used data from the Haza people of Tanzania, who presumably already have cooperation, so I’m not sure what data they’re using to back up claims of emergence. I can’t read the article because I don’t have institutional access any more, so I’d be keen to hear thoughts others have.

Here’s the abstract:

Social networks show striking structural regularities, and both theory and evidence suggest that networks may have facilitated the development of large-scale cooperation in humans. Here, we characterize the social networks of the Hadza, a population of hunter-gatherers in Tanzania. We show that Hadza networks have important properties also seen in modernized social networks, including a skewed degree distribution, degree assortativity, transitivity, reciprocity, geographic decay and homophily. We demonstrate that Hadza camps exhibit high between-group and low within-group variation in public goods game donations. Network ties are also more likely between people who give the same amount, and the similarity in cooperative behaviour extends up to two degrees of separation. Social distance appears to be as important as genetic relatedness and physical proximity in explaining assortativity in cooperation. Our results suggest that certain elements of social network structure may have been present at an early point in human history. Also, early humans may have formed ties with both kin and non-kin, based in part on their tendency to cooperate. Social networks may thus have contributed to the emergence of cooperation.

The Great Mystery of the Vanishing Phonemes

It’s been well over a year since I first wrote about the relationship between phoneme inventory size and demography (see here and here). Since then, I have completed a thesis examining this relationship further, especially in the context of the relative roles of demography and tradeoffs between other linguistic subsystems (namely, a language’s lexicon and its morphological complexity). Outside my own bubble, the topic has exploded in popularity, culminating in the publication of Quentin Atkinson’s paper, Phonemic diversity supports a Serial Founder Effect Model of Language Expansion from Africa. It really hit home how big the topic was when I saw that the New York Times had picked up on the article. For me, this was a double-edged sword: obviously, I saw myself as the phoneme-guy over at Replicated Typo, so having someone else take this niche topic and make it popular dented my ego somewhat, but it was also a positive development in that the idea was now going to get the attention it deserved…

… Well, it sort of did and didn’t. Atkinson raised two major theoretical points in his paper. The first, and the one I’m interested in, made the link between phoneme inventory sizes, mechanisms of cultural transmission and the underlying demographic processes supporting these changes. Sadly, it was Atkinson’s second idea – that we could develop a serial founder effect model from Africa based on the phoneme inventory size – where most of the attention fell. In a methodological sense, I admired Atkinson’s approach to testing this second hypothesis, but I did feel he jumped the gun somewhat: I think more work was needed on the cultural transmission model before testing for serial founder effects. Indeed, that we haven’t developed an initial model linking the relationship between phoneme inventory size and demography, may yet prove to be Atkinson’s downfall: we should be testing multiple explanatory models (Bayesian MCMC comparison, perhaps?) rather than taking a one-size-fits-all approach.

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Beware the Raconteur, my son!

We all tell stories. Be it in the elegant prose of a finely-crafted novel or merely relaying the day’s events to someone else, this capacity for storytelling is something found across our various cultures and has its roots deep in our prehistory. Stories are powerful tools with which we understand the world and share social information. They can also be dangerous. In the art of weaving together a tale, details might be omitted, others highlighted and some manipulated. Simple stories, where we abstract away from our complex and messy lives, are especially prone to this narrative fallacy, where we take facts and force an explanation into them, which, in the words of Nassim Nicholas Taleb, is misleading when it “increases our impression of understanding”. A similar warning is made in this brilliant video by Professor Tyler Cowen (of Marginal Revolution):

N.B. The featured picture is of the painting The Boyhood of Raleigh by John Everett Millais. The story behind its use here is simple: it appears on the storytelling page of wikipedia. It also began me on a quest of hyperlink jumps, but that’s another story… Yawn.

The Stoned Ape Theory of Speech Origins

Outside the world of evolutionary linguistics I used to spend some of my time working in a charity shop. Of the many dull moments, much of which spent bickering with overzealous bargain hunters about the arbitrary nature of our pricing, there were a few gems of conversation. On one of these days, I found myself conversing with several people about language change, when one of the customers chimed in with something I hadn’t heard before. He said, quite confidently, that the origin of speech and language lay in our ancestor’s proclivity for getting stoned. I humoured him on the magic mushroom hypothesis of speech origins, until he decided to share his wisdom about the foretold destruction of our society in 2012 (at which point I directed him to our copy of Emerich’s latest disasterpiece). Still, it appears he wasn’t completely barmy, at least on the speech origins front, as there is a Stoned Ape theory of human evolution by one Terence McKenna (from Wikipedia):

The mushroom, according to McKenna, had also given humans their first truly religious experiences (which, as he believed, were the basis for the foundation of all subsequent religions to date). Another factor that McKenna talked about was the mushroom’s potency to promote linguistic thinking. This would have promoted vocalisation, which in turn would have acted in cleansing the brain (based on a scientific theory that vibrations from speaking cause the precipitation of impurities from the brain to the cerebrospinal fluid), which would further mutate the brain. All these factors according to McKenna were the most important factors that promoted evolution towards the Homo sapiens species. After this transformation took place, the species would have begun moving out of Africa to populate the rest of the planet. Later on, this theory by McKenna was given the name “The ‘Stoned Ape’ Theory of Human Evolution”.

I’m fairly sure this just offloads part of the craziness onto McKenna, but I might name drop the theory next time I’m looking for a more lively reaction when discussing language origins.

N.B. This is one of my many posts that was written some time ago. I decided to publish in 2012 just in case the customer was right about our impending doom. With that out of the way, we can now focus on the critical issues surrounding the size of a language’s phoneme inventory and the distribution of Psilocybe cubensis.

Animal Cognition & Consciousness (II): Metacognition & Mentalizing

As I wrote in my last post, three kinds of behaviours are most often discussed in debates about animal consciousness and cognition:

“1. Mirror self-recognition

2. Tests of metacognition;

3. Metacognition of others’ mental states” (Gómez 2009: 45)

After having discussed the first capacitiy in my previous post, I will discuss the latter two in this post, starting with metacognition, that is being aware of one’s own knowledge states, and then turn to being aware of other’s mental states.

Metacognition.

Being aware of one’s own mental states, i.e., reflective consciousness, surely seems to be one of the most crucial components of self-awareness. In one paradigm used to test for metacognitive awareness, monkeys were trained to select, out of a number of two or more images, the one that is identical to an image they have been shown earlier. As is to expected, the monkeys’ performance progressively deteriorated the longer the delay was between the sample image and the selection task.

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Animal Cognition & Consciousness (I): Mirror Self-Recognition

Darwin made a mistake. At least that is what Derek Penn and his colleagues (2008) claim in a recent and controversial paper in Behavioral and Brain Sciences. Darwin (1871) famously argued that the difference between humans and animals was “one of degree, not of kind.”

This, according to Penn et al. is of course true from an evolutionary perspective, but in their view,

“the profound biological continuity between human and nonhuman animals masks an equally profound discontinuity between human and nonhuman minds” (Penn et al. 2008: 109).

They hold that humans are not simply smarter, but human cognition differs fundamentally and qualitatively from that of other animals.

One pervasive proposal is that we do not simply possess a unique set of cognitive capacities, but that it might be consciousness itself that is uniquely human as well, a view that goes back at least to Descartes (Burkhardt & Bekoff 2009: 41). However, there are also many scholars and researchers who agree that there is evidence for higher-order cognition in nonhuman animals ( ‘animals’ after this) and that they might possess at least some degree of consciousness (Burkhard & Bekoff 2009: 40f.).

In this and my next post, I will write about three kinds of phenomena that are most often discussed in debates on whether animals have some form of higher-order cognition and consciousness or not: self-awareness, awareness of one’s own cognitive states, and awareness of others’ cognitive states and intentions.

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Deictic Gestures in Ravens

Ravens can point. It’s scary how clever birds can be.

Guys! Guys! Guys!

Ravens can point. It’s scary how clever birds can be. People keep sending me this paper so I thought I’d link to it here so that people know I’ve seen it and stop bothering me (I actually don’t mind being bothered, especially if it’s about interesting things like this, please don’t stop). Abstract below.

Around the age of one year, human children start to use gestures to coordinate attention towards a social partner and an object of mutual interest. These referential gestures have been suggested as the foundation to engage in language, and have so far only been observed in great apes. Virtually nothing is known about comparable skills in non-primate species. Here we record thirty-eight social interactions between seven raven (Corvus corax) dyads in the Northern Alps, Austria during three consecutive field seasons. All observed behaviours included the showing and/or offering of non-edible items (for example, moss, twigs) to recipients, leading to frequent orientation of receivers to the object and the signallers and subsequent affiliative interactions. We report evidence that the use of declarative gestures is not restricted to the primate lineage and that these gestures may function as ‘testing-signals’ to evaluate the interest of a potential partner or to strengthen an already existing bond.

If you’re interested in reading about referencial gestures in humans and chipanzees and why these things are relevant to the evolution of language you should read Michael’s post here.

Reconstructing linguistic phylogenies – a tautology?

So I thought I should begin my first post on here with a nice and gentle introductory sentence, but I realise that pointing out the increased use of computational phylogenetic tools on cultural and particularly linguistic data to the avid readers of this blog is probably a pretty pointless exercise.

There is of course a lot to say about parallels between biological and cultural evolution, and some of the work using computational tools has given us new insights into yet unanswered (and even hitherto unasked!) questions regarding language and language change. But today I’d like to share some thoughts on a particular “application” of phylogenetic tools, the methodology of which I find a bit odd, even though it is arguably the simplest evolutionary analogy of them all: using computational phylogenetics to reconstruct linguistic phylogenies.

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The Declining Academic Performance of Men

PZ Myers points to a TED video of Philip Zimbardo (see below) that links the declining academic performance of men with arousal addiction: here, the transition from boys to men in our modern society is characterised by “digitally rewired” brains that are in search of constant arousal etc etc. Like Myers, I’m sceptical of these claims, but I think they are certainly worth investigating, just not in the fashion employed by Susan Greenfield (you know, she of pseudo-neuroscientific fame). What I would like to see answered is: Do all Internet-influenced societies see this general trend of declining academic performance in men?

Another research question we might want to test, or control for in our hypothetical study, is whether or not there is a correlation between the number of female teachers and male academic performance? I haven’t bothered to look into the literature on this, so maybe a study has already been done, but female teachers certainly appear to outnumber their male counterparts in many corners of the globe (especially in primary school education). In Wales, for instance, I was astonished to find that 74.7% of teachers are female. My point: there might be a more obvious underlying cause as to why women are outperforming men, other than the rise of the zombie-generation of internet-addicted gamers. Still, I’m going to go with the cop-out approach and claim there are numerous factors underpinning male achievement (or lack of) in academia and beyond. I just wanted to point out that, in any study purporting to provide answers about declining educational attainment, you first really need to look at who is doing the teaching.

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Never mind language, emotions are in a category of their own

A new paper in the journal ‘Emotion’ has presented research which has implications for the evolution of language, emotion and for theories of linguistic relativity.

A new paper in the journal ‘Emotion’ has presented research which has implications for the evolution of language, emotion and for theories of linguistic relativity. The paper, entitled ‘Categorical Perception of Emotional Facial Expressions Does Not Require Lexical Categories’, looks at whether our perception of other people’s emotions depend on the language we speak or if it is universal. The results come from the Max Planck Institute for Psycholinguistics and Evolutionary Anthropology.

Human’s facial expressions are perceived categorically and this has lead to hypotheses that this is caused by linguistic mechanisms.

The paper presents a study which compared German speakers to native speakers of Yucatec Maya, which is a language which has no labels which distinguish disgust from anger. This was backed up by a free naming task in which speakers of German, but not Yucatec Maya, made lexical distinctions between disgust and anger.

The study comprised of a match-to-sample task of facial expressions, and both speakers of German and Yucatec Maya perceived emotional facial expressions of disgust and anger, and other emotions, categorically. This effect was shown to be just as significant across the language groups, as well as across emotion continua (see figure 1.) regardless of lexical distinctions.

The results show that the perception of emotional signals is not the result of linguistic mechanisms which create different lexical labels but instead shows evidence that emotions are subject to their own biologically evolved mechanisms. Sorry Whorfians!

References

Sauter DA, Leguen O, & Haun DB (2011). Categorical perception of emotional facial expressions does not require lexical categories. Emotion (Washington, D.C.) PMID: 22004379