People often express excitement to each other when encountering an object that they have shared together previously in some special way. This study investigated whether 14‐month‐old infants know precisely what they have and have not shared in a special way (and with whom). In the experimental condition an adult and infant shared an object (the target) excitedly because it unexpectedly reappeared in several places. They then shared 2 other objects (the distractors) in a more normal fashion. Later, the adult reacted excitedly to a tray containing all 3 objects and then made an ambiguous request for the infant to hand “it” to her. There were 2 control conditions. In 1 of them, a different adult, who knew none of the 3 objects, made the ambiguous request. In the other control condition, the adult who made the request had previously experienced the objects only alone, while the infant looked on unengaged. Infants in the experimental condition chose the target object more often than the distractors and more often than they chose it in either control condition. These results demonstrate that 14‐month‐old infants can identify which one of a set of objects “we”—and not just I or you alone—have had a special experience with in the past.

We investigate young children’s sensitivity to minimal group membership. Previous research has suggested that children do not show sensitivity to minimal cues to group membership until the age of five to six, contributing to claims that this is an important transition in the development of intergroup cognition and behavior. In this study, we investigated whether even younger children are sensitive to minimal cues to group membership. Random assignment to one of either of two color groups created a temporary, visually salient minimal group membership in 3 and 4-year-old study participants. Using explicit measures, we tested whether children preferred minimal group members when making social judgments. We find that, in the absence of any knowledge regarding the two groups, children expressed greater liking for ingroup than outgroup targets. Moreover, children estimated that ingroup members would share their preferences. Our findings demonstrate that from early in development, humans assess unknown others on the basis of minimal cues to social similarity and that the perception of group boundaries potentially underlies social assortment in strangers.

Despite the apparent robustness of language learning in humans, a large number of children still fail to develop appropriate language skills despite adequate means and opportunity. Most cases of language impairment have a complex etiology, with genetic and environmental influences. In contrast, we describe a three-generation German family who present with an apparently simple segregation of language impairment. Investigations of the family indicate auditory processing difficulties as a core deficit. Affected members performed poorly on a nonword repetition task and present with communication impairments. The brain activation pattern for syllable duration as measured by event-related brain potentials showed clear differences between affected family members and controls, with only affected members displaying a late discrimination negativity. In conjunction with psychoacoustic data showing deficiencies in auditory duration discrimination, the present results indicate increased processing demands in discriminating syllables of different duration. This, we argue, forms the cognitive basis of the observed language impairment in this family. Genome-wide linkage analysis showed a haplotype in the central region of chromosome 12 which reaches the maximum possible logarithm of odds ratio (LOD) score and fully co-segregates with the language Re-use of this article is permitted in accordance with the Terms and Conditions set out at http://www3.interscience. wiley.com/authorresources/onlineopen.html impairment, consistent with an autosomal dominant, fully penetrant mode of inheritance. Whole genome analysis yielded no novel inherited copy number variants strengthening the case for a simple inheritance pattern. Several genes in this region of chromosome 12 which are potentially implicated in language impairment did not contain polymorphisms likely to be the causative mutation, which is as yet unknown.1 Joint first authors.