For the deer on the Isle of Rum it was mating season, but for Gerald Lincoln the nights were lonely. He was on the island to study their breeding cycle, and would not see his girlfriend for weeks at a time. As the chance to see her approached, Lincoln noticed something strange. His face stubble seemed to grow faster. To check that this was the case, he decided to weigh his shavings every morning, and indeed they were heavier by the day. From this he deduced something remarkable: that the level of testosterone, which determines the pace of beard growth, must be controlled by the cerebrum, the part of the brain from which complex thoughts emerge. The more he thought about his girlfriend, the higher his testosterone rose and the faster his beard grew.
He wrote a paper about it, which the prestigious scientific journal Nature agreed to publish. Highly unusually, the piece appeared anonymously, to spare his mother from the knowledge that he was having sex before marriage.
The truly old days, there was also that interim moment when it would have been her father spared such news.