Cultural Induciton is Hard

Chater and Christiansen (2010) argue that culturally transmitted systems such as language are easier to learn than natural systems because they have adapted to learner's biases, so their intuitions will likely be correct. Being a speaker of one of the morphologically most complex languages in the world, I'm not so sure...

Maggie Tallerman gave a keynote speech at this year's EvoLang conference. A section of it used grammatically acceptable and unacceptable sentences in Welsh to illustrate the point. As a somewhat lapsed Welshspeaker, whose knowledge of Mutation was never great, I was a bit embarrassed to find I wasn't sure if the examples were correct. Last month, too, Mike Dowman gave a talk at Edinburgh University emphasising how impressive it is that we all make the same grammaticality judgements about sentences we have never seen before.

I've long wondered whether this is the case with Welsh mutation. Consonant mutation, or 'Treiglo' in Welsh, occurs in many Celtic languages and is a terrible affliction for the second language learner. In a number of (grammatical) contexts, the initial consonant of a word (nouns and verbs) changes to another. For instance, 'kitchen' in Welsh is 'cegin' [k3gIn], but 'his kitchen' is 'ei gegin' [g3gIn] and 'her kitchen' is 'ei chegin' [X3gIn].

There are three forms of mutuation - soft, nasal and aspirate. The Wikipedia page on Welsh Mutation gives a broad overview. The contexts they apply in are extensive, for example:

• Nouns after the preposition 'in'
• After imperatives.
• After the personal pronoun (my)
• Singular feminine nouns after the definite article (but not words beginning in ll or rh)
• In the negative form of verbs in the Short Future Tense
• Masculine nouns after 'three' and all nouns after 'six'

The rules of mutation in old Welsh were much simpler: It only occured for feminine nouns after the definate article. However, presumaply by a process of analogy, the 'rules' spread and became more complex. And here's the point I'm trying to make: Welsh morphology may be so complex, and subject to so much change by analogy, that there is very little agreement between people.

I'm not saying that mutuation is unsystematic. There's even an automatic mutuation checker online. However, it always annoys me when syntacticians cite some examples that they haven't actually gone out and tested.

Now, this may be an intuition I have from school. I grew up speaking Welsh, both my parents speak Welsh and I went to a Welsh-medium nursery, primary and secondary school where we were not allowed to speak English. Despite this, I'm not a confident speaker, especially after 7 years outside of Wales. I was particularly bad at mutation (although my English spelling was, and still is, equally as bad). We had it drilled into us with tables and excersises, but I still can't really do it properly. This is partly because of the minority langauge status of Welsh, and the fact that everybody spoke English as a form of rebellion. The influence of English has been felt in other areas of Welsh such as Subject-Verb order, too.

However, I've always felt guilty about not being able to speak the mothertongue properly. Then I became a linguist and found a way out: All along, my teachers had been prescribing language, and that prescription was a few generations old. In terms of language evolution, the language the children speak is the correct language (the descriptivist approach).

Long story short, I conducted my own grammaticality judgement experiment. I couldn't find a grammaticality judgement for Welsh mutation online, nor any information about how well learners pick it up (please send me links if you know of any!). Neither am I a trained syntactician, so I have no real idea how to do an experiment, nor do I have access to money to employ participants.

So I decided to do it in the form of a facebook quiz, using Quibblo. I found example sentences from an instructional pamphlet and took one from each major context. I then created alternative mutations for each sentence. Participants were presented with an English equivalent of each sentence, and asked to indicate which sentences they thought were correct. Participants could make more than one choice.

You can take the quiz here and view the results here.

12 people participanted, mainly schoolfriends since this was distributed via facebook. This is a good point rather than a bad point, since we're more likely to have been exposed to the same linguistic environment (and indeed been in frequent contact). However, many of these may be, like me, somewhat out of practice. On the other hand, 11 indicated they were 'fluent' and 1 'intermediate' speakers of welsh. All but one came from South Wales. All particpants chose only one answer in 17 out of 34 questions.

As it turned out, Quibblo wasn't a very good choice - it only records totals, not individual records of participant's choices. Anyway, here's some analysis.

For each setence, I worked out the average agreement. This is the likelyhood of any two people agreeing that at least one form was correct. For all sentences, the average agreement was 67.1% For sentences where participants only selected one answer, the average agreement was 60.9%.

Some sentences recieved 100% agreement - for the sentence 'the boy', all 12 participants chose the prescribed 'dy fachgen'. However, the sentence 'the girl' was split with two thirds going for the prescribed 'y ferch' and one third going for 'y merch'. On the other end of things, 9 participants chose 'dydd mawrth' for the meaning 'on tuesday', when the prescribed form is 'ddydd mawrth', which only 3 participants chose.

For the setences with more than two possible choices, the choices are spread. For the sentence 'I read a good book', 6 different options were selected with an average agreement of 54.5%. The worst agreement was for the sentence 'the sixth girl' with participants agreeing on average 25.5% of the time between 4 options. For this sentence, 12 participants chose 16 options, meaning that some participants thought at least two options were correct (I don't have the exact data on who chose what).

I put some tricky questions in to see what would happen. The first was designed to test whether adjacent adjectives should be mutated. That is, adjectives which follow a singular feminine noun mutate, but it's not clear whether a following adjective should too. Participants were given the sentence 'a big, tall, good girl' and given the option to mutate none, the first adjective, first and second adjectives and all adjectives. 3 participants chose to mutate only the first while 5 chose to mutate all adjectives (3 chose to mutate none and 1 chose to mutate two). The agreement was 24.2%.

The second tricky question involved loanwords. Nouns after a conjunction mutate, so participants were given the sentence 'gin and tonic' and the options 'jin a tonic' and 'jin a thonic'. Agreement was slightly better here at 84.8% in favour of the prescribed (and attested) mutated form, although one person thought both were correct.

The final one involved analogy and loanwords. I heard someone mutate 'chips', which has a [ tʃ ], which doesn't exist in Welsh to the voiced equivalent [ dʒ ]. There is no prescription here, but this makes perfect sense if mutation really does spread by analogy. Presented with the sentence 'a bag of chips', 5 participants voted for the unmutated variant and 10 for 'bag o jips' (83.3% agreement).

All in all, enough to make my old Welsh teachers weep. Of course, the sample is probably skewed and can't be verified and some might have looked the answer up etc. But part of the point of this is that, for very simple sentences, people should be choosing the same sentences.

In a forthcoming special issue of Cognitive Science (preview here), Nick Chater and Morton Christiansen argue that learning cultrually-transmitted systems is easier than learning about the natural world because cultural systems will be adapted towards a learner's biases. Therefore, a learner's intuitions and guesses are likely to be correct. That is, it's easier to co-ordinate your behaviour with other people than it is to be right about the world (an alternative name for the paper could have been 'Language Evolution: Specifically not the hardest problem in Science').

It's a great paper, and argues for my PhD thesis - that language acquisition should be looked at in the light of language evolution. However, cultrual induction may not be easier than learning about the natural world if everybody is doing something different. Consider the participants in my experiment: A child learning from them faces sources of cultural variants that not only contradict each other half of the time, but contradict themselves part of the time. At least mass and other physical attributes are Universal - gravity doesn't work differently in North Wales. However, since the data cultural learners are presented with comes from multiple people who themselves may have had different and non-overlapping sources of input, cultural learning may be pretty tricky after all.

So, there may be space in this topic for my PhD thesis: The social structure of cultural learners will have a huge impact on the ease of Cultural induction, and thus on the pressures and eventual forms of language.

Nick Chater & Morton H. Christiansen (2010). Language Acquisition Meets Language Evolution Cognitive Science