My friend Winnifred had a trip to Beijing and mailed me this postcard. On the back a line was printed:

The Chinese population amounted to around 450 million in 1949 when the People's Republic of China was founded. Today it has surpassed 1.3 billion.

Crowded picture for huge population. Nothing's wrong. But wait, look again. All of them are men! (Well, if one or two tiny heads of women hide somewhere I can't refute) If we replace them with women, it would definitely look wrong immediately, as if there's some special meaning other than population. A picture of men only wouldn't have that problem. Though it mismatches with the reality that a population consists of men and women (and others), it would never look strange because we've been so brainwashed.