During the study, participants filled in psychological questionnaires which researchers used to assess a range of issues, including whether they had a positive outlook and any mental health problems.
在研究过程中，研究人员通过问卷调查的方式，对受访者是否心态乐观、是否患有精神抑郁疾病作了深入的了解。

Lead researcher Professor Tony Cassidy said: "Sisters appear to encourage more open communication and cohesion in families. "
该项研究的负责人托尼·卡西迪教授说：“家里有姐妹更有助于家庭成员加强交流并增进凝聚力。”

"However, brothers seemed to have the alternative effect. "
“相反，兄弟们似乎只能增加家人间的隔膜。”

"Emotional expression is fundamental to good psychological health and having sisters promotes this in families."
“情感的表达对于个人心理健康有着重大作用，家有姐妹能够进一步强化这种家庭纽带。”

He said many of the participants had been brought up in families where parents had split and the impact of sisters was even more marked in these circumstances.
他说，很多参加调查的人都来自单亲家庭，姐妹关系对这些人起到了非常显著的积极影响。