The Vandenbergh effect shows that novel male presence can accelerate female puberty, while juvenile female grouping can delay it.

“The other one is the Vandenbergh effect, and this is one I alluded to in a previous episode of the podcast, which is that puberty in females can be accelerated by placing a novel sexually competent male in with a young female who has not undergone puberty. There's also a version of this, which I haven't described, which is delay of puberty where you take juvenile female animals that have not undergone puberty and you put them with more mature females of the same species, and that introduction of more females will cause a delay, a significant delay in the onset of puberty.”