Humour may develop from aggression caused by male hormones, says a study.
The study was conducted by Professor Sam Shuster, who reviewed the reaction of over 400 people while he unicycled through the streets of Newcastle upon Tyne.
In the yearlong observational study Shuster realized that the huge number of stereotypical and predictable responses he received must be indicative of an underlying biological phenomenon.
In the study, people's reactions to a sudden unexpected exposure to a new phenomenon, in this case unicycling, was observed.
The analysis found that over 90 percent of the people responded physically, for example with an exaggerated stare or a wave and almost half responded verbally, more men than women, reports British Medical Journal.
Shuster said that the sex difference was striking as 95 percent of adult women were praising, encouraging or showed concern and there were very few comic or snide remarks towards his act.
In stark contrast to this, only 25 percent of adult men responded, as did the women, for example, by praise or encouragement; instead 75 percent attempted comedy, often sarcastic.
The researcher said that equally striking was the repetitive and predictable nature of the comments from men; two thirds of their 'comic' responses referred to the number of wheels, for example - "Lost your wheel?"
Shuster also noticed that the male response differed markedly with age, as in childhood curiosity was the reaction, which changed to physical and verbal aggression in boys aged 11-13 who often tried to get him to fall off the unicycle. The responses became more verbal during the later teens, turning into disparaging 'jokes' or mocking songs.
This then evolved into adult male humour, which was characterized by repetitive, humorous verbal put-downs concealing a latent aggression.
Shuster contemplated that this is the age when men are at the peak of their virility. The 'jokes' were lost with age as older men responded more neutrally and amicably with few attempts at a jovial put-down.
As for the female response, they were subdued during puberty and late teens, normally either apparent indifference or minimal approval. It then evolved into the laudatory and concerned adult female response.
Shuster said that the simplest explanation for the change is the effect of male hormones such as testosterone, known collectively as androgens, which induce virility in men.
He added that for the evolution of humour, the observations that initial aggressive intent seems to become channelled into a verbal response that pushes it into a contrived, but more subtle and sophisticated joke, so the aggression is hidden by wit. The two then eventually split as the wit takes on an independent life of its own.
The study is published in British Medical Journal.