Human behavior is determined by a combination and interaction of heredity and environment. Such an interactionist approach to the nature versus nurture controversy is a theoretical compromise, but one which has logic and empirical validity to recommend it. Such a position avoids the pitfall of "either-or" thinking, as such thinking does not recognize that human behavior is determined by a continuum of interacting variables, some genetic and some environmental.
More specifically, human intelligence is determined by an array of genetic and environmental variables. Because there are many different kinds of intelligence, and because intelligence is not scalable, it is both impossible to qualify or quantify. This fact has not stopped cognitive researchers from trying to objectively measure intelligence by some means called the "IQ," or "intelligence quotient." These attempts to quantify intelligence are pseudoscientific at best, and racist at worst. Early researchers were excessively one-sided in their attempts to demonstrate the racial and cultural nature of IQ--one was either born with good genes, or one was biologically destined to a life of inferior status. More recent hereditarians who believe that most of one's intellectual ability is inherited do acknowledge that IQ can be environmentally increased, but they confine their optimism to the very early years of developmental childhood.
It will become clear that only an interaction between heredity and environment can adequately explain the amorphous quality (not quantity) of intelligence. Mental ability will be placed in both personal and social contexts so that its relative, chimeral nature becomes apparent.
Miles D. Storfer (1990) puts the nature versus nurture controversy into perspective in his investigation of studies designed to assess IQ correspondences among members of biological and adoptive families, as well as the abundance of studies that elucidate th...