The important question isn’t whether the glass is half empty or half full, but how it likely affects your drinking.

Wide-Rimmed or Narrow-Rimmed Glass?

A recent (July 2, 2025) article in The Wall Street Journal reported on research which indicates that people prefer wider-rimmed glasses to narrow ones, are willing to spend more on drinks in wider glasses, and are more likely to reorder drinks served in wider rimmed glasses. In addition, “Drinking from wider glasses even makes them feel better.” I dug into environmental factors that affect drinking.

Glass Size and Drinking Amount

It is well known that people eat and drink more when using larger crockery and glasses. One study found that when a bar in Cambridge served wine in larger glasses, the amount customers bought and drank increased by an average of 9 per cent.

Glass shape does not affect actual drink pours in the US but glass size does, at least in some cases. In this research, larger glass size/volume was associated with larger on-premise pours of straight shots and mixed drinks; thus, the large-glass drinks were found to contain more alcohol than drinks served in short, wide glasses. Drinks poured in short, wide glasses did not contain more alcohol than drinks poured in tall, thin glasses. (As an aside: some research shows that bars with mostly black patrons serve spirits drinks with more alcohol than bars with other patrons.)

Glass Shape and Drinking Amount

The shape of a glass can influence how much people drink, particularly with alcoholic beverages.

Studies have shown that people tend to drink faster from curved glasses compared to straight glasses. Perhaps this is because curved glasses make it harder to judge how much liquid remains, which can affect how quickly someone paces their drinking.

Tess Langfield, et. al., published reports of three laboratory experiments measuring consumption of soft drinks served in straight-sided vs. outward-sloped glasses.

• In one study, although total drinking time was the same, participants drank more in the first half of the drinking session.
• In a second study, during a bogus taste test, participants consumed less from straight-sided wine flutes than outward-sloped martini coupes.
• In a third study, looking for facial expressions associated with decreased consumption, straight-sided glasses elicited more ‘pursed’ lip embouchures, which may partly explain reduced consumption from these glasses.

Using a combination of methods, including measures of amount drunk and physiological measures, the authors suggest that “switching to straight-sided glasses may be one intervention contributing to the many needed to reduce consumption of health-harming drinks.”

Glass Shape and Drinking Speed

Researchers at the University of Bristol report that people drink more quickly from curved glasses than straight ones.

They argue that the curvy glassware makes pacing yourself a much greater challenge.

Researchers filmed a group of 159 men and women drinking either soft drinks or beer. The glasses all contained around half a pint of liquid, but some of the glasses were straight while others were very curved (a “fluted” glass with a curvy taper to a narrow base).

There was no difference in the drinking time for soft drinks.

However, for the beer drinkers there was a big difference: it took around seven minutes for people drinking from a curved glass to polish off their half pint, but 11 minutes for those drinking from a straight glass. The report said: “Drinking time is slowed by almost 60% when an alcoholic beverage is presented in a straight glass compared with a curved glass.”

Could it be that curvy glasses made it harder to pace drinking because judging how much is in the glass is more difficult for a curved shape? When researchers showed drinkers pictures of partially-filled beer glasses and asked participants to say whether they were more or less than half full, they were more likely to get the answer wrong when assessing the amount of liquid in curved glasses. The lead researcher Dr Angela Attwood told the BBC, “They are unable to judge how quickly they are drinking so cannot pace themselves.” She also said altering the glasses used in pubs could “nudge” people to drink more healthily by “giving control back”.

In addition, other research found that people were more likely to pour extra alcohol into short, wide glasses than tall, narrow ones.

Glass Color

Then, too, the color of a glass can affect how much people drink. Studies have shown that the contrast between the glass and the color of the wine influences how much people pour. For example, when pouring white wine into a clear glass, participants poured 9% more than when pouring red wine, which had a greater contrast to the glass.

Don’t Trust Yourself!

Researchers at Cornell University found that, when wine drinkers were asked to pour what they considered a normal drink, they poured about 12 percent more wine into a wide glass than a standard one. The same was true when holding a glass while pouring compared with placing the glass on a table. “People have trouble assessing volumes,” said lead author Laura Smarandescu, and, “They tend to focus more on the vertical than the horizontal measures. That’s why people tend to drink less when they drink from a narrow glass, because they think they’re drinking more.”

Thus, research shows that several external factors affect how much people drink. Studies show that larger groups also often correspond with greater alcohol consumption, especially when social norms encourage drinking. I suspect most people are aware of this social effect. But the less obvious effects of size, shape, and color of one’s glass need your attention as well. And in all cases, measure standard drinks, not “free pours.”

Why? Because there’s a whole lot of drinking going on!

How Much Do We Drink?

According to the 2023 NSDUH report, of adults ages 18 and older, 67.1% reported that they drank in the past year. Of adults ages 18 and older, 51.6% reported that they drank in the past month. Among adults ages 18 and older, 6.3% reported heavy alcohol use in the past month. (The National Institute on Alcohol Abuse and Alcoholism (NIAAA) defines heavy alcohol use for men as consuming five or more drinks on any day or 15 or more per week; for women, consuming four or more drinks on any day or eight or more per week.) And 23.5% of adults 18 and older reported binge drinking in the past month. (The NIAAA defines binge drinking according to blood alcohol levels that result when a typical adult male has five or more drinks, four or more drinks for a female, in about two hours.)

Approximately 178,000 deaths occur each year due to excessive drinking.

While bartenders and other purveyors of drinks—particularly alcoholic beverages—might claim differently, there is much evidence that people should consume less alcohol. And no amount is too little!

Bottom Line: Using the information above can reduce alcohol intake pretty painlessly, and discretely. No reason not to!