Saturday, December 9, 2006
Some interesting discoveries about pheromones
In order to prepare for my soon to start PhD studies, I have been reading a lot of neuroscience lately. I am currently reading a book called Neuroscience: Exploring the Brain by Bear et. al. (2006), a textbook that I warmly recommend to everyone interested in the field.
In this book there is a section about human pheromones which I found so fascinating that I thought I would share it with those few people who occasionally read this blog. Pheromones are basically small molecules that fall off us and are sometimes picked up by the nose of other people or (more likely) animals. Our pheromones tells our genotype and can work as a fingerprint even more accurate than the fingertip fingerprint. A bloodhound which has perhaps the most developed sense of smell of all animals has great difficulty in distinguishing between two identical twins. Fraternal twins on the other hand is piece of cake. An ewe will establish a life long memory of her lamb when it is born. Pregnant female mice will automatically trigger an abortion if they feel the smell of a male other than the one that impregnated her.
What about humans then. One rather well known, yet astonishing, effect of pheromones is the synchronization of women's menstrual period. When females are allowed to smell pads which have been under the arm of another female, their menstrual period will converge with the other females period. This happens even though the women do not feel any smell at all! Pheromones are also very much involved in our sex life, believe it or not. Evidence indicates, that by picking up pheromones we can sense whether the potential mate is a good match or not (in terms of genes). Napoleon (see picture) was probably one of the first people to realise what smells can do to your lust. He once wrote and asked Josephine not to bathe for two weeks(!), so that he could enjoy her aromas...