Where the Brain, Mind, Temperament and the Enneagram Meet with Dan Siegel
aside: I really enjoyed Siegel's book, The Developing Mind (highly recommend it, if you have the patience to plow through some dense terminology and language), and his work on the neuroscience of meditation. His other books are decent, but I found many of them to be more accessible etreads of The Developing Mind.
In this talks, he talks some about epigenetics (which I always find fascinating), and how complex the interplay between genes and the environment is.
Seigel's background in more in neurobiology, and in particular how neurobiology works in interpersonal relationships. I had never heard him talk about the enneagram before, so his perspective is interesting. Apparently he (along with some others) have done some introductory research into relating enneagram type to temperament and attachment theory.
His team's early findings are that temperament and level of attachment during childhood do not correlate to enneagram type. How securely attached someone was does correlate with mental/emotional health levels as an adult.
His other early finding is that he relates the enneagram centers to the thee basic negative emotions: anger (gut, although he thinks that's not a good term here), sadness (heart) and fear (head). He then talks about three directions of attention: inner, outer and inner/outer. Combining those predominate negative emotions and the three directions of attention yields a correspondence to the enneagram types.
He does go off on a personal theory (his own, not related to others participating in the study) about the hemispheres of the brain, relating anger to the left hemisphere, and sadness to right hemisphere. He would relate fear more with the amygdala, but suspects that it plays a roll in the other types, too. (Personally, I'm a little dubious about the relation to hemispheres of the brain to enneagram type, but time could prove me wrong... and certainly the hemispheres do have a relationship to sadness/happiness).