^Dobbs, David. The Gregarious Brain.. New York Times. July 8, 2007 [2007-09-25]. If a person suffers the small genetic accident that creates Williams syndrome, he’ll live with not only some fairly conventional cognitive deficits, like trouble with space and numbers, but also a strange set of traits that researchers call the Williams social phenotype or, less formally, the “Williams personality”: a love of company and conversation combined, often awkwardly, with a poor understanding of social dynamics and a lack of social inhibition.
^Martens MA, Wilson SJ, Reutens DC. Research Review: Williams syndrome: a critical review of the cognitive, behavioral, and neuroanatomical phenotype. J Child Psychol Psychiatry. 2008, 49 (6): 576–608. PMID 18489677. doi:10.1111/j.1469-7610.2008.01887.x.