A logical fallacy
geneticists avoid at all costs. If you look at a large portion of randomly selected people, you'll find that people with the gene
for blue eyes
tend to be bad with chopsticks. Of course, this obviously doesn't mean skill with using chopsticks is determined by the gene for eye color. It's just that people with blue eyes who are incompetent with chopsticks correlate to a non-oriental
origin. This is obviously due to a non-genetic cause called culture
Richard Lewontin uses an analogy for this: People without Y-chromosomes are usually good at knitting (in other words they tend to be women). This doesn't mean that not having Y-chromosomes causes knitting.