Fisher, Helen (2012). "We have chemistry! The role of four primary temperament dimensions in mate choice and partner compatibility". The Psychotherapist. No.52. United Kingdom: United Kingdom Council for Psychotherapy. ISSN2049-4912.: "Passionate love, obsessive love, being in love, whatever you wish to call it. [...] In short, Explorers preferentially sought Explorers, Builders sought other Builders, and Directors and Negotiators were drawn to one another."