9514695 CAREY Language is perhaps the most important conceptual capacity that separates human beings from our primate cousins. This research will explore the origins of human language, both evolutionarily and in the developing child. The focus will be on some of the numerical concepts that play an important role in the grammars of natural languages, i.e., quantifiers such as "one, another, some," the distinction between countable entities (such as objects) and noncountable entities (such as sand and liquids), and concepts of specific countable entities (such as bottles and books). The research will attempt to discover which of these concepts are available before the emergence of language in the developing child, which emerge as the infant learns their expression in a natural language, and which are available independently of language in primates, such as rhesus monkeys and cottontop tamarins. The method to be used to probe the conceptual capacity of creatures without language is simply to show magic tricks, essentially impossible events, and record when the creature registers surprise by looking for a long time at the outcome of such impossible events. If a creature is surprised at the magic trick, we can be confident that he or she conceptualized the property of the natural world that was violated in the trick. For example, earlier research has demonstrated that if infants are shown one object placed behind a screen, and then a second object, (i.e., 1 + 1), and then the screen is lowered, revealing 2 objects (the possible outcome), they show little interest. But if the screen is lowered revealing 3 objects or just 1 object, they look reliably longer at these impossible outcomes. This method has been used for many years to study the concepts of human babies, and recent research has demonstrated shown that it also yields interpretable results both with rhesus monkeys in the wild and with laboratory-housed cottontop tamarins. ***
