This chapter introduces the questions driving the book and summarizes its four main findings:

1. 1. The recent improvements in the scientific research systems in select Asian countries, that have led to an increase in the return migrations of Western-trained Asian scientists

2. 2. The increasing diversification of training pathways within the Asian scientist migration system

3. 3. How returned Asian scientists are affecting the scientific research systems and scientific cultures in the Asian research organizations where they work through their scientific remittances

4. 4. The variations that exist in the scientific research systems and cultures across Asia.

This chapter also introduces the book's foundational concepts – such as the global scientific field, brain circulation, migration systems, scientific remittances and scientific cultures. The chapter explains the research design and methods used to collect data, and provides descriptive statistics about the 119 Asian scientists interviewed for the book. These 119 scientists are divided into three groups: those who stayed in the West after their training, those who returned to their birth country, and those who halfway-returned to another Asian country.