同样是沉船，路西塔尼亚号上的生还人员男人较多，而泰特尼克号上女人和孩子较多。科学家说，这是因为两艘船的沉没时间不同，前者很快就下沉，而后者时间较长，男人需要一定的时间来克服自身的动物性，并表现出利他主义。

When an ocean liner starts taking on water, what governs whether it’s “women and children first” or “every man for himself”? According to a report in the Proceedings of the National Academy of Sciences [see: http://bit.ly/clUjR2, lead author Benno Torgler], men’s altruistic versus self-serving behavior depends on how quickly the ship sinks.

On April 14th, 1912, the Titanic hit an iceberg and took nearly three hours to slip beneath the waves. Some 1,500 people perished. And the survivors tended to be female or young. The Titanic’s women were over 50 percent more likely to make it than were the males, and children had a 15 percent better chance of being rescued than adults.

But kids were not as lucky on the Lusitania, which three years later sank just 18 minutes after being hit by a German torpedo. In this situation it truly was survival of the fittest, with healthy young males being the most likely to live to tell the tale.

While passengers on the Lusitania panicked and scrambled for survival, scientists say that those on the Titanic had enough time to override their animal survival instincts and do the chivalrous thing.

—Karen Hopkin