Modern life makes us tired, right? But research from societies in Africa and South America suggests people in the ancient world slept only 6.5 hours a night.

■1月15日，北大光华管理学院“Future leader”项目的5位学生拜访了芒格书院，与书院创始人施宏俊、主笔杨紫琳等人进行了有关阅读学习、人生规划和商业投资等话题的深入交流。