It's no secret that Silicon Valley is a playground for the young. Various high-profile VCs have straight out said they prefer funding 20-somethings, and job ads routinely (and possibly illegally) note that only "digital natives" need apply. If you want more evidence of the problem, there's no shortage of great if horrifying deep dive articles on the issue.

All of this is underpinned by the idea that, political correctness be damned, young people are simply more innovative than older folks, and given their usual lack of other life commitments, also more willing to put in the time it takes to build a billion-dollar company. If success is your only metric, this thinking goes, you'd be a fool not to prefer that recent grad in a hoodie.

There's only one problem with this controversial but still widely believed orthodoxy. The numbers don't back it up (despite Silicon Valley's supposed obsession with data).

Add a decade or two to whatever you're thinking.

How do I know? I recently checked out technologist Tim Whitwell's fascinating list of 52 things he learned this year on Medium. (Side note: what a great end of the year exercise.) At the top of that list was a link to a blog post by entrepreneurship professor Joshua Gains laying out research presented this year on the age of entrepreneurs.

Gains renders the conclusions of this work in the form of an imagined dialogue between a skeptical reader and someone armed with the facts about age and startup success. It's so clear and convincing, I'll just cite it in full:

Hold on a sec, my impression from TechCrunch is that the award winners are pretty young.

Yep, around 31 or if you look at Inc and stuff like that it is 29 years.

OK so what is it like for the US?

For new firms in the US between 2007 and 2014 (aka the Y-C years), it is 41.9.

OK but that is all firms. What about technology?

It is actually higher, 43.9 with VC backed firms 41.9 and patenting firms 44.6.

Yeah but not in Silicon Valley surely?

Nope pretty much the same.

Alright but what about successful firms? That's what the VCs care about.

In Silicon Valley, the ones with a successful exit have an average founding age of 47!

Let me underline that for you while you lift your jaw off the floor: the average age of Silicon Valley entrepreneurs who have a successful exit (i.e. sell their company for a bucket load of money or take it public) is 47 years.

Good professor that he is, Gains is careful to point out that this data isn't perfect and that research is ongoing, but he's also pretty definitive that these results "should give Silicon Valley investors types some food for thought." Preliminary or not, they should also probably encourage would-be entrepreneurs who are concerned they're too old to get a truly successful business off the ground (so should history).

Numbers don't lie. If you're old enough to look ridiculous in a hoodie, that's actually a sign your chances of startup success are greater than average, not less.