1、Although rarely showing kindness to (=Although they rarely show kindness to) contrary theories,researchers tend to praise studies that agree with their own conclusions.
2、Researchers tend to praise studies that agree with their own conclusions and they rarely show kindness to contrary theories
这两句话在语法上都是正确的,但在逻辑上 句1 似乎说不通.
句2 译成 :研究者们倾向于表扬与自己的结论相吻合的研究,很少对(与研究结论)相反的理论表现仁慈.(praise 与 show 成并列关系,不能用转折)
您再把句1翻译一下,看看结果如何?