In recent years, policymakers, service providers and researchers have highlighted the importance of early intervention programs for promoting development in young children. In this essay I will review and evaluate research focused on the development of children's cognitive abilities, particularly research focused on children from low socioeconomic status (SES) backgrounds. I will focus on two types of cognitive outcomes assessed in the literature, namely general cognitive ability and literacy and numeracy skills. I will examine the literature that places a strong focus on environmental effects as the main causal element influencing a child's cognitive development, and then turn to research that focuses more on the role played by genetics, not only in the development of children's cognitive abilities, but also its connection to SES. I will suggest that although environmental factors need to be studied and play a role in a child's development, research that places little or no emphasis on genetics is overlooking a vital aspect of children's development, therefore ultimately deficient, and has the potential to result in a less useful policy for intervention strategies. Furthermore, as findings from research focusing on the genetics of cognitive development and SES become more widely accepted and integrated into development programs and policies, there will be greater potential to close the gap between the abilities of different children, as a greater understanding of personalized education can lead to its more successful application. According to Arnold and Doctoroff (2003) significant discrepancies between children regarding their academic performance are a consequence of SES. They go on to say state ... half of the paper ... of children in the United States Part II: Relationships to behavioral development through age thirteen. Child Development, 72(6), 1868-1886. Kovas, Y., Voronin, I., Kaydalov, A., Malykh, S. B., Dale, P. S., & Plomin, R. (2013). Literacy and numeracy are more heritable than intelligence in primary school. Psychological Science, 24(10), 2048-2056.Trzaskowski, M., Harlaar, N., Arden, R., Krapohl, E., Rimfeld, K., McMillan, A., & Plomin, R. (2014) . Genetic influence on family socioeconomic status and children's intelligence. Intelligence, 42, 83-88. Tseng, J. C., Chu, H. C., Hwang, G. J., & Tsai, C. C. (2008). Developing an adaptive learning system with two sources of personalization information. Computers and Education, 51(2), 776-786.Whitehurst, G. J., & Lonigan, C. J. (1998). Child development and emergent literacy. Child development, 69(3), 848-872.