And when an orangutan in Suaq has acquired more of these tricks than its less fortunate cousins elsewhere, it has done so because it had greater opportunities for social learning throughout its life.

• 斯瓦克的红毛猩猩学会许多这种本事，因为牠们终身都有较多机会从事社会学习，其他地方的表亲没这麽幸运，学会的东西就少得多了。