The aggressive asteroids are all male:
The first asteroids discovered in the early 1800s were all fairly large objects in stable orbits between Mars and Jupiter, about 2.7 AU from the sun. They were all given female names, starting with Ceres (the first, and still the largest asteroid known). By 1898 over 300 were known, every one of them in a neat little orbit between 2 and 3 AU.
In 1898 the first orbit-crossing asteroid was discovered. This was a rock 10 kilometers in diameter, and its aphelion was about 1.78 AU from the sun, while its perihelion was 1.14 AU, meaning that at times it crossed Mars's orbit and came as close as 20 million km from the Earth. To differentiate it from the polite and well-behaved asteroids previously discovered, it was given a male deity's name: Eros. To this day, all asteroids whose orbits cross over planetary orbits are male; all the ones with "safe" orbits are female.
One consequence of this nomenclature is that all the large, long-lived asteroids are also female. Every known asteroid in the "over 10 kilometers" class has a regular orbit between planets. Male asteroids don't last very long.