When the first lot of Baby Boomers were born (1946), they were expected to live, on average, until they were 69.

They’re now expected, on average, to live to 79.

This average life expectancy is expected to further lengthen as time passes.

The members of Generation Z, the oldest of which are now in their 20s, on average are expected to live to 100 and beyond.

Health technology may or may not eventually lift Gen Zers well past that. They could be the generation that collectively hits the biological ceiling.

The big question, of late, is what they will look like when they’re old?

The reason this carries weight is because Gen Zers on TikTok are worried they’re ageing faster than Millennials, the generation that preceded them.

Just three weeks ago, The New York Times asked: ‘‘Why does Gen Z believe it’s ‘ageing like milk’?’’

Science does not back this up, unless a massive set of mutations took hold of people aged between 11 and 26 (those born between 1997 and 2013), an entire generation is not going to biologically age at a faster rate.

But what about those skin-care products targeted at tweens?

According to The Wall Street Journal: “Pre-teens now account for as much as $US200 million of the $US3 billion in annual mass-market sales of make-up, according to industry estimates.”

TikTok influencer Jordan Howlett has 12 million followers. None believe he’s 26.

There’s also plenty of encouragement from wellness and beauty sites for young girls to start a skincare routine.

A gentle cleanser morphs into the use of Retinol or other exfoliating agents.

Meanwhile, #BabyBotox on TikTok has scored hundreds of millions of views – and a whole new market for dermatologists and cosmetic doctors.

Baby Botox is regular botox – a nerve toxin that kills movement temporarily – but in microdoses for young women aged 18 and up. These doses are purported to prevent wrinkles.

And once you think you’ve seen one, you’re bound to check early and often for more to crop up.

Gen Z is the first digital generation, born into a fully formed, highly social and ruthlessly targeted online shopping world, all integrated into who you are and what you believe.

They have grown up looking at themselves, studying themselves, looking for problems with what they see, and quick to find solutions.

That kind of anxiety will age you

And what if the vaping craze really took over, and every Gen Zer was sucking down nicotine and all those flavoured ingredients day after day? Might that not take a toll on their looks? Maybe?

It’s certainly not doing any good. The crackdown on vaping by the Australian government is driven by Gen Z’s hefty consumption of e-cigarettes.

When you have 13-year-olds calling the Quitline for help with their fruity, tasty and toxic vaping addiction, we’ve gone beyond the threat of wrinkles to dealing with a “health emergency”, if not a crisis.

The Gen Zer who started it

Say hello to TikTok sensation @jordan_the_stallion8 – also known as Jordan Howlett, aged 26, but looking like a daddy professor with a salt-and-pepper beard and a nerdy wardrobe.

It was Howlett who set off the ageing Gen Z trend in a lengthy post.

“We live in a time nowadays where Millennials look way younger for their age,” he posted.

He then outed himself as a case in point, a Gen Zer turning into an old codger quickly. His followers refused to believe it.

“Ummm aren’t you like 35!???” one said.

Howlett suggests his generation is ageing faster because it is dealing with more stress in their lives than earlier generations. War. Unreliable unemployment. Little access to housing (for example).

Celebrities, in particular, are having a difficult time, because they’re ageing too.

Twitter recently dropped a bomb on Kylie Jenner, 26, one of the first Gen Zers to be born, describing her as a “rich, beautiful 46-year-old lady”.