saussure-with-money

Vocal Iconicity Challenge (Deadline Extension: August 15th)

Earlier this year I mentioned that Gary Lupyan and Marcus Perlman were running a competition to win a $1000. All you have to do is pop over to their website, record yourself doing some sounds, and then submit. The good news is that they’ve extended the deadline until August 15th. So, if you fancy yourself as the iconic vocalisation master, then go to http://sapir.psych.wisc.edu/vocal-iconicity-challenge/

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Future tense and saving money: Small number bias

Last week saw the release of the latest Roberts & Winters collaboration (with guest star Keith Chen). The paper, Future Tense and Economic Decisions: Controlling for Cultural Evolution, builds upon Chen’s previous work by controlling for historical relationships between cultures. As Sean pointed out in his excellent overview, the analysis was extremely complicated, taking over two years to complete and the results were somewhat of a mixed bag, even if our headline conclusion suggested that the relationship between future tense (FTR) and saving money is spurious. What I want to briefly discuss here is one of the many findings buried in this paper — that the relationship could be a result of a small number bias.

One cool aspect about the World Values Survey (WVS) is that it contains successive waves of data (Wave 3: 1995-98; Wave 4: 1999-2004; Wave 5: 2005-09; Wave 6: 2010-14). This allows us to test the hypothesis that FTR is a predictor of savings behaviour and not just an artefact of the structural properties of the dataset. What do I mean by this? Basically, independent datasets sometimes look good together: they produce patterns that line up neatly and produce a strong effect. One possible explanation for this pattern is that there is a real causal relationship (influences y). Another possibility is that these patterns aligned by chance and what we’re dealing with is a small number bias: the tendency for small datasets to initially show a strong relationship that disappears with larger, more representative samples.

Since Chen’s original study, which only had access to Waves 3-5 (1995-2009), the WVS has added Wave 6, giving us an additional 5 years to see if the initial finding holds up to scrutiny. If the finding is a result of the small number bias, then we should expect FTR to produce stronger effects with smaller sub-samples of data; the initial effect being washed out as more data is added. We can also compare the effect of FTR with that of unemployment and see if there are any differences in how these two variables react to more data being added. Unemployment is particularly useful because we’ve already got a clear casual story regarding its effect on savings behaviour: unemployed individuals are less likely to save than someone who is employed, as the latter will simply have a greater capacity to set aside money for savings (of course, employment could also be a proxy for other factors, such as education background and a decreased likelihood to engage in risky behaviour etc).

What did we find? Well, when looking at the coefficients from the mixed effect models, the estimated FTR coefficient is stronger with smaller sub-samples of data (FTR coefficients for Wave 3 = 0.57; Waves 3-4 = 0.72; Waves 3-5 = 041; Waves 3-6 = 0.26). As the graphs below show, when more data is added over the years a fuller sample is achieved and the statistical effect weakens. In particular, the FTR coefficient is at its weakest when all the currently available data is used. By comparison, the coefficient for employment status is weaker with smaller sub-samples of data (employment coefficient for Wave 3 = 0.41; Waves 3-4 = 0.54; Waves 3-5 = 0.60; Waves 3-6 = 0.61). That is, employment status does not appear to exhibit a small number bias, and as the sample size increases we can be increasingly confident that employment status has an effect on savings behaviour.

savings_ftr_participants

 

savings_ftr_language

 

So it looks like the relationship between savings behaviour and FTR is an artefact of the small number bias. But it could be the case that FTR does have a real effect albeit a weaker one — we’ve just got a better resolution for variables like unemployment and these are dampening the effect of FTR. All we can conclude for now is that the latest set of results suggest a much weaker bias for FTR on savings behaviour. When coupled with the findings of the mixed effect model — that FTR is not a significant predictor of savings behaviour — it strongly suggests this is a spurious finding. It’ll be interesting to see how these results hold up when Wave 7 is released.

 

EvoLangXIPlenaries2

Plenaries for EvoLang announced

The plenary speakers for EvoLang XI have been announced.  As well as standard plenaries, there are two discussion plenaries, focussed on a theme with discussants taking different positions.

The deadline for paper submission is the 4th of Setpember 2015 (see the conference website).

EvoLangXIPlenaries2

Discussion Plenaries

Language localization in the brain

Gricean communication

Single Plenaries

  • Vincent Janik (dolphin communication, Biology, University of St. Andrews)
  • Joan Bybee (usage-based grammaticalization, Linguistics, University of New Mexico)
  • Ljiljana Progovac (Evolution of Syntax, Linguistics,Wayne State University)
  • Erich Jarvis (neurobiology of birdsong, Neurobiology, Duke University)
  • Dean Falk (paleoneurology/motherese, Anthropology, Florida State University)
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Future tense and saving money: methods

Our recent paper on testing the correlation between future tense and saving money uses a variety of statistical methods, which I’ll summarise in this post.

The challenge was looking at correlations between traits of individual people while controlling for properties of their cultural history.  Saving money is an individual trait which can change in the short term, while languages are properties of groups which change over very long periods of time.  In addition, we would like to control for three sources of non-independence:  similarities between people’s economic conditions caused by them being in the same state, similarities in their language and culture caused by historical relations and similarities in their language and culture caused by cultural contact.

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Dan Dennett, “Everybody talks that way” – Or How We Think

Note: Late on the evening og 7.20.15: I’ve edited the post at the end of the second section by introducing a distinction between prediction and explanation.

Thinking things over, here’s the core of my objection to talk of free-floating rationales: they’re redundant.

What authorizes talk of “free-floating rationales” (FFRs) is a certain state of affairs, a certain pattern. Does postulating the existence of FFRs add anything to the pattern? Does it make anything more predictable? No. Even considering the larger evolutionary context in which talk of FFRs adds nothing (p. 351 in [1]):

But who appreciated this power, who recognized this rationale, if not the bird or its individual ancestors? Who else but Mother Nature herself? That is to say: nobody. Evolution by natural selection “chose” this design for this “reason.”

Surely what Mother Nature recognized was the pattern. For all practical purposes talk of FFRs is simply an elaborate name for the pattern. Once the pattern’s been spotted, there is nothing more.

But how’d a biologist spot the pattern? (S)he made observations and thought about them. So I want to switch gears and think about the operation of our conceptual equipment. These considerations have no direct bearing on our argument about Dennett’s evolutionary thought, as every idea we have must be embodied in some computational substrate, the good ideas and the bad. But the indirect implications are worth thinking about. For they indicate that a new intellectual game is afoot.

Dennett on How We Think

Let’s start with a passage from the intentional systems article. This is where Dennett is imagining a soliloquy that our low-nesting bird might have. He doesn’t, of course, want us to think that the bird ever thought such thoughts (or even, for that matter, perhaps thought any thoughts at all). Rather, Dennett is following Dawkins in proposing this as a way for biologists to spot interesting patterns in the life world. Here’s the passage (p. 350 in [1]):

I’m a low-nesting bird, whose chicks are not protectable against a predator who discovers them. This approaching predator can be expected soon to discover them unless I distract it; it could be distracted by its desire to catch and eat me, but only if it thought there was a reasonable chance of its actually catching me (it’s no dummy); it would contract just that belief if I gave it evidence that I couldn’t fly anymore; I could do that by feigning a broken wing, etc.

Keeping that in mind, lets look at another passage. This is from a 1999 interview [2]:

The only thing that’s novel about my way of doing it is that I’m showing how the very things the other side holds dear – minds, selves, intentions – have an unproblematic but not reduced place in the material world. If you can begin to see what, to take a deliberately extreme example, your thermostat and your mind have in common, and that there’s a perspective from which they seem to be instances of an intentional system, then you can see that the whole process of natural selection is also an intentional system.

It turns out to be no accident that biologists find it so appealing to talk about what Mother Nature has in mind. Everybody in AI, everybody in software, talks that way. “The trouble with this operating system is it doesn’t realize this, or it thinks it has an extra disk drive.” That way of talking is ubiquitous, unselfconscious – and useful. If the thought police came along and tried to force computer scientists and biologists not to use that language, because it was too fanciful, they would run into fierce resistance.

What I do is just say, Well, let’s take that way of talking seriously. Then what happens is that instead of having a Cartesian position that puts minds up there with the spirits and gods, you bring the mind right back into the world. It’s a way of looking at certain material things. It has a great unifying effect.

So, this soliloquy way of mind is useful in thinking about the biological world and something very like it is common among those who have to work with software. Dennett’s asking us to believe that, because thinking about these things in that way is so very useful (in predicting what they’re going to do) that we might as well conclude that, in some special technical sense, they really ARE like that. That special technical sense is given in his account of the intentional stance as a pattern, which we examined in the previous post [3].

What I want to do is refrain from taking that last step. I agree with Dennett that, yes, this IS a very useful way of thinking about lots of things. But I want to take that insight in a different direction. I want to suggest that what is going on in these cases is that we’re using neuro-computational equipment that evolved for regulating inter personal interactions and putting it to other uses. Mark Changizi would say we’re harnessing it to those other purposes while Stanislaw Dehaene would talk of reuse. I’m happy either way. Continue reading

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Future tense and saving money: no correlation when controlling for cultural evolution

This week our paper on future tense and saving money is published (Roberts, Winters & Chen, 2015).  In this paper we test a previous claim by Keith Chen about whether the language people speak influences their economic decisions (see Chen’s TED talk here or paper).  We find that at least part of the previous study’s claims are not robust to controlling for historical relationships between cultures. We suggest that large-scale cross-cultural patterns should always take cultural history into account.

Does language influence the way we think?

There is a longstanding debate about whether the constraints of the languages we speak influence the way we behave. In 2012, Keith Chen discovered a correlation between the way a language allows people to talk about future events and their economic decisions: speakers of languages which make an obligatory grammatical distinction between the present and the future are less likely to save money.

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evolutioninstitute

Become a founding member of the Society for the Study of Cultural Evolution

There is a new society for the study of cultural evolution, who are currently recruiting a base of founding members. People interested in language evolution are encouraged to join here: https://evolution-institute.org/project/society-for-the-study-of-cultural-evolution/

They encourage the following people to become founding members:

  • Academic professionals, graduate students, and undergraduate students from any discipline relevant to cultural evolution. They especially encourage the next generation of scientists to become involved.
  • Anyone (professional or nonprofessional) who is trying to accomplish positive cultural change in the real world and who would like to base their efforts on cultural evolutionary theory.
  • Anyone (professional or nonprofessional) with an intellectual interest in cultural evolutionary theory who would like to get involved and support the newly emerging field.
  • They are especially eager for our members to come from all cultures around the world—an appropriate ideal for a Society for the Study of Cultural Evolution!
alien

Learn an Alien Language!

I’ve set up a little experiment in collaboration with a small armada of co-authors (Jonas Nölle, Peeter Tinits, and Michael Pleyer). Be a pioneer in interstellar communication and try to accomplish an important mission:

http://tsamtrah.bplaced.net/

Many thanks to Thomas Hartmann for programming the online interface and to James Winters for some enormously helpful advice on the design of the experiment.

We’ll keep you posted about the results…

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Phylogenetics in linguistics: the biggest intellectual fraud since Chomsky?

A few weeks ago, Roger Blench gave a talk at the MPI entitled ‘New mathematical methods’ in linguistics constitute the greatest intellectual fraud in the discipline since ChomskyThe title is controversial, to say the least!  The talk argued, amongst other things,  that phylogenetic methods are less transparent and less replicatable than traditional historical reconstruction.   Here are I argue against those points.

I felt like I should respond online, because Roger Blench made the talk slides available online (a similar set of arguments are more fully expressed by here).

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Dan Dennett on Patterns (and Ontology)

I want to look at what Dennett has to say about patterns because 1) I introduced the term in my previous discussion, In Search of Dennett’s Free-Floating Rationales [1], and 2) it is interesting for what it says about his philosophy generally.

You’ll recall that, in that earlier discussion, I pointed out talk of “free-floating rationales” (FFRs) was authorized by the presence of a certain state of affairs, a certain pattern of relationships among, in Dennett’s particular example, an adult bird, (vulnerable) chicks, and a predator. Does postulating talk of FFRs add anything to the pattern? Does it make anything more predictable? No. Those FFRs are entirely redundant upon the pattern that authorizes them. By Occam’s Razor, they’re unnecessary.

With that, let’s take a quick look at Dennett’s treatment of the role of patterns in his philosophy. First I quote some passages from Dennett, with a bit of commentary, and then I make a few remarks on my somewhat different treatment of patterns. In a third post I’ll be talking about the computational capacities of the mind/brain.

Patterns and the Intentional Stance

Let’s start with a very useful piece Dennett wrote in 1994, “Self-Portrait” [2] – incidentally, I found this quite useful in getting a better sense of what Dennett’s up to. As the title suggests, it’s his account of his intellectual concerns up to that point (his intellectual life goes back to the early 1960s at Harvard and then later at Oxford). The piece doesn’t contain technical arguments for his positions, but rather states what they were and gives their context in his evolving system of thought. For my purposes in this inquiry that’s fine.

He begins by noting, “the two main topics in the philosophy of mind are CONTENT and CONSCIOUSNESS” (p. 236). Intentionality belongs to the theory of content. It was and I presume still is Dennett’s view that the theory of intentionality/content is the more fundamental of the two. Later on he explains that (p. 239):

… I introduced the idea that an intentional system was, by definition, anything that was amenable to analysis by a certain tactic, which I called the intentional stance. This is the tactic of interpreting an entity by adopting the presupposition that it is an approximation of the ideal of an optimally designed (i.e. rational) self-regarding agent. No attempt is made to confirm or disconfirm this presupposition, nor is it necessary to try to specify, in advance of specific analyses, wherein consists RATIONALITY. Rather, the presupposition provides leverage for generating specific predictions of behaviour, via defeasible hypotheses about the content of the control states of the entity.

This represents a position Dennett will call “mild realism” later in the article. We’ll return to that in a bit. But at the moment I want to continue just a bit later on p. 239:

In particular, I have held that since any attributions of function necessarily invoke optimality or rationality assumptions, the attributions of intentionality that depend on them are interpretations of the phenomena – a ‘heuristic overlay’ (1969), describing an inescapably idealized ‘real pattern’ (1991d). Like such abstracta as centres of gravity and parallelograms of force, the BELIEFS and DESIRES posited by the highest stance have no independent and concrete existence, and since this is the case, there would be no deeper facts that could settle the issue if – most improbably – rival intentional interpretations arose that did equally well at rationalizing the history of behaviour of an entity.

Hence his interest in patterns. When one adopts the intentional stance (or the design stance, or the physical stance) one is looking for characteristic patterns. Continue reading

Culture, its evolution and anything inbetween