"begin to picture the brain metaphorically as a tangled ball of Christmas lights. When you plug it in, there are strands that light up perfectly and there are dark zones where a single burned-out bulb has caused a line to go out. If the bulb for Exchanging-Smiles-With-Mother doesn't light up, then Empathy won't be kindled farther along the strand, or Playfulness, or Theory of Mind (the insight that other people have different thoughts from yours). The electrical current won't reach the social-skill set, the communication skills, creativity, humor or abstract thinking."

-Melissa Fay Greene, writing in the NY Times on autism and development