Answer:
environment
Explanation:
Environmental factors play an important role in the nature and nurture phenomenon of research. If two identical twins get separated after birth then nature i.e, genetics as well as nurture i.e, the environment both play an important role in the development of the child.
According to the research, genetics plays a 60% role in the development of a child whereas the environment plays a 40% role.
After getting separated after birth, the development of both the child would be different depending on the different cultures and environments in which they both were.