Because is why: Children’s acquisition of topoi through why questions (2023)

Abstract: In this paper we look at how children learn the underlying principles of commonsense reasoning, sometimes referred to as topoi, which are prevalent in everyday dialogue. By examining the utterances of two children in the CHILDES corpus for whom there is extensive longitudinal data, we show how children can elicit topoi from their parents by asking why-questions. This strategy for the rapid acquisition of topoi peaks at around age three, suggesting that it is a critical step in becoming a fully competent language user.

## introduction children pick up language with remarkable ease. from not being able to speak at all they learn in a few years to be fully competent language users. this does not just mean being able to communicate meaning coded in words and phrases -it also involves inference and association from the linguistic expressions and non-linguistic actions used to a meaning in use. @xcite discusses how such inferences draw on globally accepted facts ("the sun sets in the west"), norms ("one loves one's family"), and other principles of reasoning ("if you can do a and a is more difficult than b you can also do b"). principles like these often implicitly underpin conversational moves, episodes in conversation and entire discourses, and have been claimed to be essential to capturing linguistic meaning in use @xcite . in their account ducrot and anscombre draw on aristotelian dialectic and rhetoric, and use the term topoi (sg. topos) for such principles. familiarity with the topoi that are acceptable in a community is also important for being proficient in a new language, as well as interpreting the behaviour of others. we see evidence of this in (1), discussed in @xcite where a father and son engage in a discussion about whether or not lee, the son, could still play football even though he is not going to school because of illness. both dave and lee are reasoning in a pragmatically competent way, despite evoking different topoi such as "one should rest when one is ill", "disease spreads less outdoors" (and possibly "fresh air is healthy") and "if one is well enough to do something less important and more exerting, one is also well enough to do something more important and less exerting". lee: cos of my cough. dave: how can you play football and not go to school then? lee: cos i was going out in the fresh air, i'm alright when i'm out in the fresh air. dave: so why aren't you going to school then? lee: i'm in the class room all day dad. ## why why? previous research shows that in adult conversation, topoi can be elicited by using why-questions @xcite . in many instances, what constitutes a good answer to a why-question constitutes an acceptable enthymeme when combined with the queried utterance, as is the case in (1), where "because of my cough" is an acceptable enthymematic reason for not going to school because of the acceptability of, for example, an underlying topos that when you are ill you should not mix with other people because you are contagious. where a dialogue participant cannot access or accommodate an appropriate topos, the asking of a why-question should be a particularly useful strategy to get one's interlocutor to make the topos more explicit. indeed, when asked (fake) why-questions in a text-based dialogue experiment, people do provide the "missing" premises @xcite . one reason that a dialogue participant may not have access to appropriate topoi is that there may be more than one applicable topoi available. however, in the case of young children it is often the case that a child lacks any topos that would make an argument coherent altogether. we hypothesise that asking why-questions to increase the acceptable topoi one has access to is also a learning strategy for children, in line with evidence that children's why-questions are used for explanations and arguments (bova and arcidiacono, 2013) foot_2 once they have acquired a sufficient grounding in areas such as syntax @xcite . such a strategy -extrapolating and applying general principles of reasoning from minimal input (even when these go awry as in ( 2 )) shows how children are capable of utilising informative learning signals to learn from limited data. ## method for this exploratory study, we used two longitudinal cases from childes. the specific sources and their characteristics are described in ## results & discussion as can be seen in figures 2 and 3 , both children have a peak of why-questions. for lara, this occurs between 27 and 36 months whilst for thomas this occurs between 36 and 42 months. interestingly, while both show a distinct peak in why-questions (from asking none prior to this peak), this is relatively lower for thomas, who peaks at approximately 1.5 why-questions per 1000 words, compared to lara's 4. these differences in individual children are not apparent in the data shown in figure 1 . in this regard it is also informative to consider the input each child received in terms of why-questions, since acquisition of wh-questions in general has been linked to the input from the caregiver(s) @xcite . while we cannot, of course, extrapolate from the available data to the total exposure of each child to why-questions, it is notable that in the available data, thomas is also exposed to fewer why-questions than lara, though the general patterns of why-questions they encounter is similar in both cases, rising steadily as the child asks more why-questions themselves. more fine-grained analysis is necessary to see how and whether these apparent contingencies have a direct impact on the child's interactive behaviour. in terms of the use of because, once again we see that both children have a peak at around the same age range. interestingly though, thomas' peak in the use of 'because' coincides with his peak in the figure 3 : thomas: frequency of 'why' and 'because' per 1000 words by age in months use of 'why', but is greater (in the order of 5-6 words per 1000). this corresponds to the relatively greater input of 'because' from other speakers that we see in the thomas data, as compared to lara. interestingly, these children seem to have potentially different strategies for acquiring topoi, with the differences not fully explainable by broad differences in input that we have looked at here. ## conclusions as we have shown, children tend to have a peak of why-questions at around 3 years of age, which we speculate is due to their rapid acquisition of topoi at around this age. the development of the two children we have looked at in this paper is consistent with this. they also exhibit a peak in the use of 'because', although even in our small sample, the ways in which they use the available resources differs between the children suggesting there may be different pathways to acquiring topoi. one hypothesis is that if children are exposed to more explicit topoi (in the form of 'because' explanations) they may not have such a necessity to ask explicit whyquestions. further exploration of children's use of linguistic and pragmatic markers and their relationship to the interactive input is necessary to further elucidate these issues. one of our plans for future research is to look at if and how 'why @xcite . these are intuitively codependent strategies (if you ask me why, i might expect a because), but how productive these strategies are has, to the best of our knowledge, not previously been investigated -particularly in child language data. more fine-grained analysis is necessary to investigate whether there are other aspects of the children's pragmatic acquisition strategy that covaries with these two linguistic markers, but we leave such analysis to future work. although our data does not conclusively say that children whose parents use more 'because' explanations do the same, they suggest a connection between child behaviour and the behaviour of care givers in this respect. however, further work is needed to look at the relations between the frequency of why-questions and because-clauses in the language produced by caregivers and children. example ( 6 ) also suggests avenues for future work, since it indicates that the child has already acquired a topos and is now concerned with how far this topos can be generalised (in this case, the child has learnt that one usually wears gloves when gardening to keep one's hands clean, but that this is not necessary). learning the scope and range of topoi is a critical -and non-trivial-task for the language learning child, as demonstrated by greta's overextention of the topos in (2). it is noteworthy in this regard that young children are able to pick up and modify the topoi they have access to from very little input -something that is still beyond the capabilities of conversational ai.