Violence and Genetics:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1458834/
Note: an actual scholarly article and not a youtube link. 😄
/Whirly's trolling
"A wealth of twin and adoption studies confirms that individual differences in violent/antisocial behavior are heritable..."
"It is unlikely that genes directly code for violence; rather, allelic variation is responsible for individual differences in neurocognitive functioning that, in turn, may determine differential predisposition to violent behavior."
"Given that existing studies have used very different populations and measures and have not always controlled for concurrent environmental risk or other genetic influences, contradictory findings are perhaps to be expected. Recent research suggests that genetic vulnerability to violence conferred by the low-activity allele of MAOA-L variant may become evident only in the presence of an environmental trigger of maltreatment..."
Basically, we don't know for sure if it is environment or genetics in a classic "chicken or egg." Keep in my mind that my position is "it's both." One thing is clear, the Middle Eastern peoples are violent because they are violent (tautological but that's how it works: if raised in a violent environment, you will more likely, compared to a non-violent environment, be violent...odd that we already know violence breeds violence).