被告知被收养一事时。

Psychoanal Q. 1977 Jan;46(1):1-22.

Clinical data from the analyses of three adoptees document the deleterious effect of telling children under three years of age about their adoptive status. The knowledge, as well as the experiences, of being an adoptee imposes the need for defensive reactions which affect developmental process, cognitive function, object relationships, and fantasy life.

对三名被收养者的分析得出的临床数据证明了，向三岁以下儿童告知其收养身份会产生有害影响。作为被收养者的认知以及经历，会引发防御反应的需求，而这会影响发育过程、认知功能、客体关系和幻想生活。