Paul McGrath cracks a smile ahead of Manchester United's 1984 season. PA/PA Archive/Press Association Images
No Swapsies

What's the secret to a happy life? Check your old trading cards

Scientists study old trading cards to crack happiness code.


We all swapped them as kids – be it Panini ’90 or Texaco GAA All-Star – but collectable trading stickers and cards, may hold more information than we realised.

American scientists have proven – thanks to baseball cards – that smiling actually makes you live longer.

Writes science blog

Of course, it isn’t actually the smiling itself that makes people live longer, but rather the positive emotions and outlook one can infer from how much a person smiles in his or her photographs.

Smile intensity in childhood photographs has been shown to be correlated with future marriage stability and satisfaction. However, researchers have generally been limited in what correlations they can test, because it’s hard to put together large groups for which you’ve got both photos and detailed biographical information.

That’s where baseball players enter the picture.

These baseball boffins were able to trawl through the archive of the sport’s cards which goes back to the 19th century, and there is no shortage of biographical data on those playing America’s game.

Discover Magazine quoted researchers at Michigan’s Wayne State University explain:

We were able to include many additional factors known to influence longevity because of the group we elected to evaluate. We focused on Major League Baseball (MLB) players because detailed statistics are available for each player (dating back prior to 1900), and because MLB players represent a homogeneous occupational group.

We (and other researchers) have used this database to examine numerous factors related to longevity. The first step of the Cox proportional hazards regression model included college attendance, marital status, birth year, career length, age at debut year, and BMI.

Whatever that means, nerd.

Ultimately, they found that smile intensity really did do a good job in predicting longevity, accounting for 35% of the total variability in players’ survival chances.

Now I wonder would it apply to county final pen pics and World Cup sticker albums?