What are researchers rediscovering through their studies?

参考解析：

细节理解题。根据第二段第一句和第二句“‘While we teach, we learn,’ said Roman philosopher Seneca. Now scientists are bringing this ancient wisdom up-to-date.”可知，教别人知识的时候自己也在学习，现在，科学家们正在将这一古老的智慧带入现代。，所以A项正确；根据第三段第一句“Researchers have found that students who sign up to tutor others work harder to understand the material, ”可知，研究人员发现，报名参加来辅导其他人的学生在理解材料方面更加努力，B项表述正相反，错误；根据第三段第五句“This suggests their higher IQs result from the time they spend teaching their siblings.”可知，他们的高智商源于他们花在教导弟弟和妹妹上的时间。所以C项错误；D项未提及，所以排除。故选A。