All nouns in Spanish have grammatical gender, with obligatory gender marking on preceding articles (e.g., la and el, the feminine and masculine forms of "the," respectively). Adult native speakers of languages with grammatical gender exploit this cue in on-line sentence interpretation. In a study investigating the early development of this ability, Spanish-learning children (34-42 months) were tested in an eye-tracking procedure. Presented with pairs of pictures with names of either the same grammatical gender (la pelota, "ball [feminine]"; la galleta, "cookie [feminine]") or different grammatical gender (la pelota; el zapato, "shoe [masculine]"), they heard sentences referring to one picture (Encuentra la pelota, "Find the ball"). The children were faster to orient to the referent on different-gender trials, when the article was potentially informative, than on same-gender trials, when it was not, and this ability was correlated with productive measures of lexical and grammatical competence. Spanish-learning children who can speak only 500 words already use gender-marked articles in establishing reference, a processing advantage characteristic of native Spanish-speaking adults.

Mastery of grammatical gender is difficult to achieve in a second language (L2). This study investigates whether persistent difficulty with grammatical gender often observed in the speech of otherwise highly proficient L2 learners is best characterized as a production-specific performance problem, or as difficulty with the retrieval of gender information in real-time language use. In an experimental design that crossed production/comprehension and online/offline tasks, highly proficient L2 learners of Spanish performed at ceiling in offline comprehension, showed errors in elicited production, and exhibited weaker use of gender cues in online processing of familiar (though not novel) nouns than native speakers. These findings suggest that persistent difficulty with grammatical gender may not be limited to the realm of language production, but could affect both expressive and receptive use of language in real time. We propose that the observed differences in performance between native and non-native speakers lie at the level of lexical representation of grammatical gender and arise from fundamental differences in how infants and adults approach word learning.

The ideal of scientific progress is that we accumulate measurements and integrate these into theory, but recent discussion of replicability issues has cast doubt on whether psychological research conforms to this model. Developmental research—especially with infant participants—also has discipline‐specific replicability challenges, including small samples and limited measurement methods. Inspired by collaborative replication efforts in cognitive and social psychology, we describe a proposal for assessing and promoting replicability in infancy research: large‐scale, multi‐laboratory replication efforts aiming for a more precise understanding of key developmental phenomena. The ManyBabies project, our instantiation of this proposal, will not only help us estimate how robust and replicable these phenomena are, but also gain new theoretical insights into how they vary across ages, linguistic communities, and measurement methods. This project has the potential for a variety of positive outcomes, including less‐biased estimates of theoretically important effects, estimates of variability that can be used for later study planning, and a series of best‐practices blueprints for future infancy research.

Three experiments using online processing measures explored whether native and non-native Spanish-speaking adults use gender-marked articles to identify referents of target nouns more rapidly, as shown previously with 3-year-old children learning Spanish as L1 (Lew-Williams & Fernald, 2007). In Experiment 1, participants viewed familiar objects with names of either the same or different grammatical gender while listening to Spanish sentences referring to one object. L1 adults, like L1 children, oriented to the target more rapidly on different-gender trials, when the article was informative about noun identity; however, L2 adults did not. Experiments 2 and 3 controlled for frequency of exposure to article-noun pairs by using novel nouns. L2 adults could not exploit gender information when different article-noun pairs were used in teaching and testing. Experience-related factors may influence how L1 adults and children and L2 adults—who learned Spanish at different ages and in different settings—use grammatical gender in realtime processing.

Young children’s language experiences and language outcomes are highly variable. Research in recent decades has focused on understanding the extent to which family socioeconomic status (SES) relates to parents’ language input to their children and, subsequently, children’s language learning. Here, we first review research demonstrating differences in the quantity and quality of language that children hear across low-, mid-, and high-SES groups, but also—and perhaps more importantly—research showing that differences in input and learning also exist within SES groups. Second, in order to better understand the defining features of ‘high-quality’ input, we highlight findings from laboratory studies examining specific characteristics of the sounds, words, sentences, and social contexts of child-directed speech (CDS) that influence children’s learning. Finally, after narrowing in on these particular features of CDS, we broaden our discussion by considering family and community factors that may constrain parents’ ability to participate in high-quality interactions with their young children. A unification of research on SES and CDS will facilitate a more complete understanding of the specific means by which input shapes learning, as well as generate ideas for crafting policies and programs designed to promote children’s language outcomes.