The Earlier, The Better.

Targeted measures Heckman pointed out that while the development of childhood skills is strongly influenced by the family and social environments, many rural parents in China migrate to the cities for work. James Heckman, a Nobel laureate in economics, told the conference via video link that early childhood development has a high rate of return on investment. This family environment had slowed down many aspects of the sisters' development, including their language skills. [Extracted from the article]