Rising lead levels in the U.S. from 1950 through the 1970s neatly track increases in violence 20 years later, from the '70s through the '90s. (Violence peaks when individuals are in their late teens and early 20s.) As lead in the environment fell in the '70s and '80s thanks in large part to the regulation of gasoline violence fell correspondingly.

WSJ: Neurocriminology: Inside the Criminal Mind

Siddique had been fascinated by computers from his early teens, eventually enrolling in a computing technician's course at the Central College of Commerce in Glasgow.

BBC: NEWS | UK | Scotland | The quiet student plotting terror

Criminality peaks in the late teens and early twenties, a period that would have been from the mid 1960s on up until the late 1980s.

FORBES: Kevin Drum on the Molecule

The band is made up of some 90 girls - whose ages range from mid teens to early 20s - who, in teams, appear daily in their own theatre and regularly on television, in adverts, and in magazines.

BBC: AKB48 pop star shaves head after breaking band rules