Former professional baseball pitcher Brandon McCarthy had a shower thought: did people age faster in the past? So, he did what you normally do in these situations. Ask Twitter about getting old in the past.

When you think about it, evolution is a very slow process and humans are more or less the same basic issue model that they’ve been for years, so it can’t be the case, right? However, people started replying to McCarthy with old photos of their parents where 20-year-old dads look like they’re about to retire. And that’s irrefutable evidence right there!

Continue scrolling and check out these vintage photos and the hilarious debate.

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However, if we got serious for a moment, we’d discover that different humans age differently, and that’s the way it has been. A study of nearly one thousand 38-year-olds revealed that while most had biological ages close to the number of birthdays they had notched up, others were in quite worse or better health.

Researchers used 18 physiological markers, including blood pressure, organ function, and metabolism, to evaluate the biological age of the participants. For some, the past dozen years had taken no obvious toll on their body’s biology.

Others, however, hadn’t been so lucky. A good many participants had biological ages in the 50s, and in one “extreme case” a person had a biological age of 61, meaning that for every birthday over the past dozen years, their body had aged 3 years, thus shortening the life span significantly.

“The overwhelming majority are biologically in their mid-40s or younger, but there are a handful of cases who are in pretty bad shape. In the future, we’ll come to learn about the different lives that fast and slow aging people have lived,” said Daniel Belsky at Duke University in North Carolina.

“Our goal was to see if we can measure aging in young people,” said Belsky. “It’s becoming increasingly clear that aging is really the cause of much of the disease and disability burden we face, but our existing science is based on aging in older people who already have a lot of age-related diseases.”

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Others thought this thread was perfect for making jokes:

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