Here’s the surprising reason people are drinking more wine than they used to

More Americans are drinking wine than ever before—which probably comes as no surprise—but why are each of us drinking so much of it? According to a Cambridge scientist, it’s not stress and the fact that, well, wine is delicious. It’s actually because our wine glasses are bigger than they used to be.

Speaking at the Hay festival, Theresa Marteau, director of the behavior and health research unit at Cambridge University, said the size of the glass matters because the bigger it is, the more we are inclined to drink.

“There has been a gradual increase in capacity from 65ml to 450ml,” she said. “The key period was the 1990s.”

Marteau’s team looked at 18th- and 19th-century wine glasses and the evidence was right there—today’s glasses are definitely bigger. In an experiment, they then found the amount of wine purchased daily increased by almost 10 percent when sold in larger glasses.

In a separate study, the team also discovered that the same amount of wine was perceived to be less in larger glasses compared to smaller glasses, and narrower glasses compared to wider glasses. Those differences could also contribute to changes in the amount of wine people drink.

Marteau says these concepts also apply to food and that plates and dishes are also getting bigger.

“If we made sizes smaller for all food tableware, for every occasion we encounter food, the effects of size would be to reduce how much we consume by up to 16 percent in adults per day,” she said.

There you have it, science says it’s totally cool to blame the glass after you accidentally finish the bottle.

Marteau’s team has some fascinating research into all sorts of topics, including whether bottle size affects the amount of Coca-Cola consumed at home. You can check out more of their research here.