HBD: Too Simplistic an Explanation?

Frequently, anti-HBDers have accused me of espousing a very simplistic explanation for racial achievement differences. They contend that many cultural, environmental, and social effects intermingle in creating these disparities. With such a complex interweaving of external influences, anti-HBDers conclude these clearly influential factors preclude a genetic explanation. Thus, individuals who support HBD are championing a simplistic, reductionist explanation.

I have two main objections to this. First, their argument presumes HBDers advocate an entirely genetic model. Yet, no sane person believes intelligence and behavior to be entirely determined by heredity and this point has been repeated ad nausem by heavyweights such as Arthur Jensen.

Second, significant environmental effects do not negate the notion that intelligence is about 70% inherited. A complex system, stimulated by a number of complex causes, can still be primarily defined by a single, somewhat simple cause.

I'll give an analogy to illustrate the point. Basketball is a multifaceted game that requires its participants to have quickness, agility, strength, and athleticism. Each game is fast-paced, unpredictable, and each move is subject to numerous variables. Let's engage in a thought experiment. Take 1,000 white men (control for race and gender) above 5'10'' and 1,000 below 5'10''. Split them into teams of 5 and have a round robin tournament. I guarantee the teams comprised of the taller men will have a higher winning percentage than teams comprised of the shorter men. We can contribute this to a number of external factors, such as the taller men probably have more playing experience or the shorter men might have been subject to stereotype threat.

But it's rather obvious, even in such a complex system as a game of basketball with multiple external factors, one simple number basically explains the entirety of the data: height. The taller men were conferred a tremendous, inherent advantage due simply to their height.

Similarly, people venture through a multifarious world of social networks and cultural impulses, but that single inherited g factor seems to explain a great deal of the available data. I don't care if it seems simple, it's the best explanation for the available data.