A social media post has prompted a heated debate about the real purpose of 'baby on board' signs and stickers. They're a common sight in the rear windscreens of cars and other vehicles on roads in the UK and around the world, but many people have their own views on what they are actually for. Some claim they are intended to alert other motorists to drive especially carefully around the vehicle, while others have different views.

The mystery was even lampooned in a 1993 episode of The Simpsons, in which Marge Simpson presents her husband Homer with a baby on board sign, saying: "Now people will stop intentionally ramming our car", providing him the inspiration to write a hit song for his short-lived barbershop quartet. Now a social media post has re-ignited the debate.

Writing on X, formerly Twitter, one user, @BonkDaCarnivore, said: "I used to think these stickers were the dumbest things ever. Like anybody was going to drive more carefully around a car because they had a stupid sticker on it.

"Then my wife informed me 'no you idiot, it's so if you get into a wreck the fire department knows to look for a baby in the wreckage'...and I went ahead and decided maybe they weren't so bad."

But other X users had their own theories. One said: "I do drive more carefully when I see that sticker tho. I assume whoever is driving would be also checking on the baby so they might be distracted."

Another said: "As a firefighter I’ve never looked for a window sign or sticker. A car seat, stuffed animal, or toys at a crash scene is a triggering sign more than anything for us."

Someone else wrote: "My husband is a paramedic. I asked him if they look for these in an accident, he said 'no'."

And others raised concerns about the idea. One said: "That was the original purpose, and why they used to be on suction cups instead of stickers, so it could be removed when the baby wasn't on board. So many departments wasted time looking for babies that weren't there to the detriment of other passengers that they now ignore them."

And another wrote: "These stickers are pasted on the car. Even when the car owner goes out somewhere without the baby the sticker remains. Now if the car owner is severely injured in an accident, will emergency services spend precious minutes searching for a baby they can't find in the wreckage?"

And someone else said: "It's better to put one up - people will slow down a bit because there's a baby in the car."

Motoring and safety experts have moved to provide some clarity on the issue. Road Safety GB said: "The stickers are designed to alert the emergency services that a baby or small child is in the car in the event of a collision, and to encourage other drivers to be more careful around them."

But, speaking to qz.com, paramedic Paul Maxwell said: “I’ve never heard that theory before. I surveyed my crew and everyone thinks it's to warn people to be extra cautious driving behind so as to not crash into them.”

Posting on Instagram, Nikki Jurcutz, former paramedic and co-founder of Australian first aid training program Tiny Hearts Education, said: "Do paramedics look for ‘Baby on Board’ signs? It’s a common sight, right? But are they a must for parents?

"I get asked a lot about these signs and whether or not they are important for parents to have on their cars. You might have heard that you NEED a 'Babe on Board' sign on your car in case of an accident so that paramedics know to look for your child.

"This is a myth! During my time as a paramedic, I was trained to assess the whole situation.

"Paramedics aren’t just relying on a baby on board sign, they are looking for clues that a child may have been in the vehicle, like car seats, and baby bags. Paramedics will thoroughly check all parts of the car and around the area too. The paramedics on the scene will be there assessing the full picture with or without the baby on board sign on the car."

According to qz.com, the signs were first invented in 1984 by Massachusetts resident Michael Lerner after he had driven his 18-month-old nephew home. “People were tailgating me and cutting me off,” he said. “For the first time, I felt like a parent feels when they have a kid in the car.”