Who theorized that peer relations develop as peers cooperate with each other?

It was theorized by soviet psychologist Lev Semyonovich Vygotsky. he is the founder of the research tradition of studying higher psychological functions, which became known since the critical works of the 1930s as a "cultural-historical theory" in psychology. he is the  Author of publications, works on the cognitive development of the child . there is a team of researchers named after him " circle of Vygotsky-Luria."

Fiscal policy because it refers to the use of government spending and tax policies to influence macroeconomic conditions, including aggregate demand, employment, inflation, and economic growth.