In a previous post I wrote of a personality and matching test at Chemistry.com that was developed by researcher Helen Fisher. We are already seeing some possible patterns in how her types correspond to socionic types, and I encourage readers to take the test if they haven't already and share their results in that post.
There was a great deal of data that people vary in terms of their expression of dopamine and norepinephrine, serotonin, estrogen and oxytocin and testosterone. I culled from the academic literature all of those data points that show that these particular brain-chemical systems are related to certain aspects of personality. And I saw constellations of temperament traits that seemed to be associated with these chemicals.