"S"pontaneous "a"ttention to "n"umber (SAN) is the tendency to notice the relatively abstract attribute of number despite the presence of other attributes. According to nativists, an innate concept of one to three directs young children's attention to these "intuitive numbers" in everyday situations--even before they acquire language. According to the nonnativists, language in the form of number words or counting selectively guides children's attention to known, but not to unknown, numbers. This dissertation research was conducted for the purpose of testing these views and clarifying the role language plays in the development of early number concepts. The dissertation reports on two studies. The first study systematically examined whether and how age, collection size, and heterogeneity of the objects affect toddlers' tendency to focus on number. Each of 37 participants between the ages of 2 and 4.25 years was shown 36 different collections of 2, 3, and 4 items that were homogeneous, semihomogeneous, or heterogeneous. Age, collection size, and collection make-up were found to have significant effects on children's tendency to attend to number, which is inconsistent with the nativists' hypothesis of an innate cardinal concept of three. The second study was conducted to further clarify this issue and to include data on children's verbal number performance. The results revealed that SAN with "two" and "three" was significantly correlated with a child's preferred verbal quantification strategy and with the child's ability to verbally label a collection without counting, respectively. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]