[cmiles74]

The poster wondered what environmental factors these family members may have shared, social class is definitely one such factor.

Are you arguing that may not be the case? I think you would need more information about the poster's family to make that assertion.

[truthaway54321]

No, I'm saying that there is a demonstrated causal arrow from genes to intelligence. The evidence is less clear on the causality of social class and intelligence, however, so simply asserting it as a causative factor is not an effective rebuttal.