同樣是沉船，路西塔尼亞號上的生還人員男人較多，而泰特尼克號上女人和孩子較多。科學家說，這是因為兩艘船的沉沒時間不同，前者很快就下沉，而后者時間較長，男人需要一定的時間來克服自身的動物性，并表現出利他主義。

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