A new study has found puberty can be induced by sexual touch in female rats.

While hormones were shown to play the largest role, social cues such as sexual touching can affect puberty in mammals.

The researchers found that just having young male and female rats in the same cage accelerated changes in an area of the brain associated with sexual development called the ‘genital cortex’.

This was not seen when the sexes were separated by wire mesh or kept within same-sex cages.

When the researchers touched the young female rats’ genitals using a lubricated brush, they reached sexual maturity faster and their genital cortex expanded significantly.

It has been known for some time that social cues can either accelerate or delay puberty in mammals, but it has not been clear which signals are crucial, nor how they affect the body and brain, and in particular the possible reorganisation of the brain.

“The effects of sexual touch on puberty and the genital cortex are remarkable since you wouldn’t expect this area of the brain to expand at this stage of development,” says researcher Constanze Lenschow from Humboldt University, Berlin.

“The representation of the body changes in the cerebral cortex,” says fellow researcher Michael Brecht.

“In particular the genital cortex doubles in size. Our results help to understand why the perception of our body changes so much during puberty.”

Thus, changes of the body and the concurrent changes in the brain during puberty are not merely a matter of hormones – they are also co-determined by sexual experience.

The study is accessible here.