In developed countries, we have less to fear from infectious parasites, but much more to fear from infectious memes. So, instead of opening our bodies to ambient germs, we open our minds to ambient culture, to determine if we can stay sane throughout the onslaught. When you see teenagers and young adults posting their interests in music, books, and film on their MySpace websites, consider the costly signaling principles at work. If they have exposed themselves to a lot of death metal, Chuck Palahniuk, and David Lynch, and they are still sane enough to sustain a reasonable conversation through email or instant messaging, they have credibly proven their openness and psychosis-resistance

I find it rather hard to believe that an unconscious social mechanism for showcasing resilience to infectious diseases would control our responses to memetic influences. Sure, they propagate in an analogous manner, but the actual mechanisms are completely different, and demonstrating resilience against foreign memes to show reproductive fitness doesn't sound like something humans would have done in the ancestral environment. It strikes me as implausible that our unconscious would associate them.