ABSTRACT
The ability to think mathematically is a central aspect of human cognition, and the development of this ability has been a topic of intense study. This literature, in large part, paints a general picture of the development of number knowledge. Much less attention has been paid to individual differences in number knowledge, to variations in number-relevant input, or to the relation between number knowledge and input. A confluence of research findings and societal goals is fueling an increased interest in understanding individual differences in early mathematics knowledge. First, it is now clear that individual differences in math knowledge emerge early, and that these early differences predict later achievement (e.g., Duncan et al., 2007). Second, early differences in mathematics achievement are associated with socio-economic status (SES) (e.g., Jordan, Huttenlocher, & Levine, 1992; Jordan, Levine, & Huttenlocher, 1994; Lee & Burkam, 2002; Saxe, Guberman, & Gearhart, 1987), which is an impediment to diversifying the workforce in the science, technology, engineering, and mathematics (STEM) disciplines (e.g., Arnold, Fisher, Doctoroff, & Dobbs, 2002). Finally, workforce demands for people with high levels of mathematical skill are increasing while American children lag children in other countries in math achievement (e.g., Gonzales et al., 2004; OECD, 2007). Research aimed at increasing our understanding of the factors that contribute to individual differences in mathematics achievement is central to addressing these issues.
