Frequency, redundancy, and context in bilingual acquisition.

We report findings from a corpus-based investigation of three young children growing up in German-English bilingual environments ( = 3;0, Range = 2;3-3;11). Based on 2,146,179 single words and two-word combinations in naturalistic child speech (CS) and child-directed speech (CDS), we assessed the degree to which the frequency distribution of CDS predicted CS usage over time, and systematically identified CS that was over- or underrepresented in the corpus with respect to matched CDS baselines. Results showed that CDS explained 61% of the variance in CS single-word use and 19.

The effects of family, culture and sex on linguistic development across 20 languages.

Languages vary in their complexity; caregivers vary in the way they structure their communicative interactions with children; and boys and girls can differ in their language skills. Using a multilevel modelling approach, we explored how these factors influence the path of language acquisition for young children growing up around the world (mean age 2-years 9-months; 56 girls). Across 43 different sites, we analysed 103 mother-child pairs who spoke 3,170,633 utterances, 16,209,659 morphemes, divided across 20 different languages: Afrikaans, Catalan, Cantonese, Danish, Dutch, English, Farsi, French, German, Hebrew, Icelandic, Irish, Italian, Japanese, Mandarin, Norwegian, Portuguese, Spanish, Swedish and Turkish.

Working memory training improves children's syntactic ability but not vice versa: A randomized control trial.

We tested several hypotheses about the relation between syntax and working memory (WM). In a pretest/posttest randomized control trial, 104 native Cuban Spanish-speaking children (M = 7 years 2 months; 54 girls) took part in syntax training in their first language, syntax training in their second language, WM training, or no training (control). Compared with the control, children in the training conditions showed cognitive transfer from WM to syntax but not from syntax to WM.

Dying to cooperate: the role of environmental harshness in human collaboration.

It has been proposed that environmental stress acted as a selection pressure on the evolution of human cooperation. Through agent-based evolutionary modelling, mathematical analysis, and human experimental data we illuminate the mechanisms by which the environment influences cooperative success and decision making in a Stag Hunt game. The modelling and mathematical results show that only cooperative foraging phenotypes survive the harshest of environments but pay a penalty for miscoordination in favourable environments.

The structure of executive functioning in 11 to 14 year olds with and without special educational needs.

The structure and development of executive functioning (EF) have been intensively studied in typically developing populations, with little attention given to those with Special Educational Needs (SEN). This study addresses this by comparing the EF structure of 132 adolescents (11-14 years-old) with SEN and 138 adolescents not requiring additional support (Non-SEN peers). Participants completed verbal and non-verbal assessments of key components of EF: inhibition, working memory and switching.

Effort Perception is Made More Accurate with More Effort and When Cooperating with Slackers.

Recent research on the conditions that facilitate cooperation is limited by a factor that has yet to be established: the accuracy of effort perception. Accuracy matters because the fitness of cooperative strategies depends not just on being able to perceive others' effort but to perceive their true effort. In an experiment using a novel effort-tracker methodology, we calculate the accuracy of human effort perceptions and show that accuracy is boosted by more absolute effort (regardless of relative effort) and when cooperating with a "slacker" rather than an "altruist".

Goldilocks Forgetting in Cross-Situational Learning.

Given that there is referential uncertainty (noise) when learning words, to what extent can forgetting filter some of that noise out, and be an aid to learning? Using a Cross Situational Learning model we find a U-shaped function of errors indicative of a "Goldilocks" zone of forgetting: an optimum store-loss ratio that is neither too aggressive nor too weak, but just the right amount to produce better learning outcomes. Forgetting acts as a high-pass filter that actively deletes (part of) the referential ambiguity noise, retains intended referents, and effectively amplifies the signal. The model achieves this performance without incorporating any specific cognitive biases of the type proposed in the constraints and principles account, and without any prescribed developmental changes in the underlying learning mechanism.

Inhibitory Control Predicts Grammatical Ability.

We present evidence that individual variation in grammatical ability can be predicted by individual variation in inhibitory control. We tested 81 5-year-olds using two classic tests from linguistics and psychology (Past Tense and the Stroop). Inhibitory control was a better predicator of grammatical ability than either vocabulary or age.

Productivity of Noun Slots in Verb Frames.

Productivity is a central concept in the study of language and language acquisition. As a test case for exploring the notion of productivity, we focus on the noun slots of verb frames, such as __want__, __see__, and __get__. We develop a novel combination of measures designed to assess both the flexibility and creativity of use in these slots.

Group-level expression encoded in the individual.

Smaldino proposes a conceptual extension to the theory of cultural evolution to include emergent group-level traits as a unit of selection. It is important to recognize the role that group-level traits have played in the evolution of human culture. However, the emergent group-level trait of division of labor provides an illustrative example that is implementable within the existing framework of cMLS theory and may not even need a departure from the standard model.

The role of semantics, pre-emption and skew in linguistic distributions: the case of the un-construction.

We use the Google Ngram database, a corpus of 5,195,769 digitized books containing ~4% of all books ever published, to test three ideas that are hypothesized to account for linguistic generalizations: verbal semantics, pre-emption and skew. Using 828,813 tokens of un-forms as a test case for these mechanisms, we found verbal semantics was a good predictor of the frequency of un-forms in the English language over the past 200 years-both in terms of how the frequency changed over time and their frequency rank. We did not find strong evidence for the direct competition of un-forms and their top pre-emptors, however the skew of the un-construction competitors was inversely correlated with the acceptability of the un-form.

The communicative contexts of grammatical aspect use in English.

In many of the world's languages grammatical aspect is used to indicate how events unfold over time. In English, activities that are ongoing can be distinguished from those that are completed using the morphological marker -ing. Using naturalistic observations of two children in their third year of life, we quantify the availability and reliability of the imperfective form in the communicative context of the child performing actions.

The scope of usage-based theory.

Usage-based approaches typically draw on a relatively small set of cognitive processes, such as categorization, analogy, and chunking to explain language structure and function. The goal of this paper is to first review the extent to which the "cognitive commitment" of usage-based theory has had success in explaining empirical findings across domains, including language acquisition, processing, and typology. We then look at the overall strengths and weaknesses of usage-based theory and highlight where there are significant debates.

Semantics of the transitive construction: prototype effects and developmental comparisons.

This paper investigates whether an abstract linguistic construction shows the kind of prototype effects characteristic of non-linguistic categories, in both adults and young children. Adapting the prototype-plus-distortion methodology of Franks and Bransford (1971), we found that whereas adults were lured toward false-positive recognition of sentences with prototypical transitive semantics, young children showed no such effect. We examined two main implications of the results.