make a case for something:1,to explain why something should be done 2,to explain that something is true 这里适用第二种解释,解释某件事情是对的,真实存在的.scholars have tried to make a case for acquisitiveness,competitiveness,and selfishness as innate human trait.意译为：学者们已经尝试着证明人性生而具有求知欲、竞争欲及自私自利.