Matt Hogan pointed me to this Chris Roach post on the music used in al Qaeda propaganda videos. The post is worth a read and Roach links to some exemplars for those who haven't listened to any of the stuff. It got me wondering about the actual neuroscience and psychology of music. This is an area where the research is fairly thin, but there were two papers of particular interest that I found, which together hint at an interesting picture.

Peretz et al (1998) (PDF) studied a patient who sustained sequelar lesions in both of her temporal lobes, which left her unable to recognize once-familiar melodies, discriminate between musical sequences, or sing more than a single pitch, despite being able to sing well before the damage had occurred. Her other cognitive capabilities were otherwise totally unimpaired. Now here's the weird part: she claimed to still be emotionally affected by music even though she couldn't articulate why. Subsequent study bore this out: her emotional responses to music correlated very highly with those of a fully-functional control group. After controlled experiments which you can read about in the paper, Peretz et al concluded that there was a dissasociation between structural and emotional cognition in music.

This in itself isn't really surprising, but it neatly underscores the "under the hood" nature of so much of our cognition. Subtle cues can have deep effects that we're not consciously aware of.

The second paper is by Blood and Zatorre (2001) (PDF), who found using PET scans that the "shiver down the spine" effect of pleasurable pieces of music correlated with increased activity in the emotion & arousal centers, and also the reward/motivation centers of the brain. These are much the same areas that get activated for addictive drugs, and it's plausible the association of these sensations with videos glorifying terrorist attacks can can have subtle psychological effects.

Recall that per Marc Sageman (see Razib's earlier post on Sageman's book here, and overviews of Sageman's work here and here), in the vast majority of cases he studied, social bonds arose before ideological commitment. The common pattern seems to be that young disaffected men form isolated cliques, one or more of them starts taking an interest in Islamic extremism (usually through visits to extremist mosques), and draws the rest of the group in as well. This dynamic bears a resemblance to the role of social circles in the forming of drug addictions as well.

No real culminating point to all this, other than to gesture at the vague outline of what psychological role jihadi music might play in the phenomenon of Islamic terrorism.

Addendum from Razib: It seems to me that too much of the public and foreign policy discourse operates with the assumption of Rationality(Culture) = Behavior. That is, inferences based on cultural axioms are the way in which we operate. In the current conversation about Iran I am a bit disturbed at the tendency to take the rhetoric of the radical political leaders at face value, or, interpret them through our own world-views (ie., instead of positing rational inferences from the axioms, the nutsoness of a set of axioms or behaviors in the light of our own values allows us to quickly deduce that the Other is insane and inscrutable). A less gross, but nevertheless overly simple, representation might be Rationality(Mind(Culture)) = Behavior. That is, our behavior is a function of the architecture of the mind channeling culture and guided by a few basic rational principles. If you are to kill an enemy it often behooves one to invade their house and map the lay of land so you might wait in ambush. In argumentation I have found it far easier to convince individuals to take the knife and cut their own throat because their beliefs demand it rather than moving earth and sky and showing them my truth and wielding the knife myself. There is more than one leash with ties man in this world, and it is important that we manipulate all of them.