2006年发表在JournalofNeurogenetics的一份研究中,多伦多贝加斯医院的心理学家招募了一弟俩和们的亲组成的家庭。
In a 2006 study published in the Journal of Neurogenetics, psychologists at Baycrest Hospital in Toronto recruited families composed of an adult brother and sister and their biological parents.