Three studies (N=144) investigated how toddlers aged 18 and 24 months pass the surprise-mark test of self-recognition. In Study 1, toddlers were surreptitiously marked in successive conditions on their legs and faces with stickers visible only in a mirror. Rates of sticker touching did not differ significantly between conditions. In Study 2, toddlers failed to touch a sticker on their legs that...

A large body of research shows that vocabulary does not develop independently of grammar, representing a better predictor of the grammatical complexity of toddlers' utterances than age. This study examines for the first time the characteristics of vocabulary and grammar development in Slovenian-speaking infants and toddlers using the Slovenian adaptation of the MacArthur-Bates Communicative Dev...

To what extent do toddlers have shared vocabularies? We examined CDI data collected from 14,607 infants and toddlers in five countries and measured the amount of variability between individual lexicons during development for both comprehension and production. Early lexicons are highly overlapping. However, beyond 100 words, toddlers share more words with other toddlers in comprehension than in ...

This study investigated the influence of emotion on toddlers’ prosocial behavior in instrumental helping tasks with an unfamiliar adult. The goals were to examine whether early prosocial behavior was affected by (1) the adult’s expressions of sadness (in contrast to a neutral expression) as a cue of need and (2) toddlers’ emotion understanding. Thirty-five 18to 20-month-olds participated in eig...

Joint engagement (JE) is a state in which two people attend to a common target. By supporting an infant's attention to the target, JE promotes encoding of information. This process has not been studied in toddlers despite the fact that language and social interaction develop rapidly in this period. We asked whether JE modulates object discrimination in typically developing toddlers. In a pilot ...

Objective : To examine development of early expressive lexicons in toddlers with cleft palate to determine whether they differ from those of noncleft toddlers in terms of size and lexical selectivity. Design : Retrospective. Patients : A total of 37 toddlers with cleft palate and 22 noncleft toddlers. Main Outcome Measures : The groups were compared for size of expressive lexicon reported on th...

Adults recognize that if event A predicts event B, intervening on A might generate B. Research suggests that although preschoolers draw this inference much like adults, toddlers do not (Bonawitz et. al, 2010). Here we look at whether toddlers’ failure is domain-general (i.e., they lack an adultlike concept of causality that integrates prediction, intervention, and agency) or domain-specific (i....

Our goal in this study was to examine whether controlled pretense signal presentation by an adult promoted pretend play behavior in toddlers. Seventy-two Japanese toddlers (24 toddlers in the 18-month-old group, 24 toddlers in the 24-month-old group, and 24 toddlers in the 30-month-old group) participated in one of two experimental conditions: signal and signal-less. In the signal condition, th...

Novel words (like tog) that sound like well-known words (dog) are hard for toddlers to learn, even though children can hear the difference between them (Swingley & Aslin, 2002, 2007). One possibility is that phonological competition alone is the problem. Another is that a broader set of probabilistic considerations is responsible: toddlers may resist considering tog as a novel object label beca...

We examined the contents of language-mediated prediction in toddlers by investigating the extent to which toddlers are sensitive to visual shape representations of upcoming words. Previous studies with adults suggest limits to the degree to which information about the visual form of a referent is predicted during language comprehension in low constraint sentences. Toddlers (30-month-olds) heard...