While we're on the topic of heritability coefficients, it's worth pointing out that fear of determinism is unjustified. The simplest way to get across that point is that what we should fear is lack of free will, not determinism. Genes may happen to ultimately determine a phenotype as part of a complex causal network, and yet that might tell us little about the potential for malleability and change or the roll of intention in that outcome.

fun fact: C. elegans male and hermaphrodite sperm are different sizes; male sperm are bigger

worm porn: http://www.youtube.com/watch?v=cXx35u7zLxs