Is the glass half full or half empty?

A cliché about optimism and pessimism is that a pessimist says the glass is half empty, while an optimist says the glass is half full. There even is a Wikipedia page.

There are other more creative replies. A physicist says the glass really is half-filled with water and half-filled with air. An engineer says the glass is twice as big as it needs to be. A bartender says for $2 I can refill the glass with orange juice, or for $5 I can add a fifth of a glass of vodka, and make it into Screwdrivers. (That’s a specific version of a Tom Peters quote - that the real question instead should be how do I fill the glass?). If the glass scares you half to death, then you have glassophobia.

Back on January 30, 1997 a Dilbert cartoon had the following clever dialogue:

Ratbert: A pessimist says the glass is half empty. An optimist says it’s half full.

Dilbert: Did you put your lips on my glass again?

Ratbert: And the engineer says…

Dilbert: It’s a good thing I put half of my water in a redundant glass.

On September 1, 2018 another Dilbert cartoon which inspired this post had some less clever dialogue:

Pointy-haired Boss: A pessimist says the glass is half empty. An optimist says it is half full.

Dilbert: The engineer says the glass is too big.

Pointy-haired Boss: The manager says the engineer should shut his pie hole. 

There was an article by Diana Booher on pages 12 and 13 of the February 2010 issue of Toastmaster magazine titled The Link Between Language and Leaders which said:

“As a presenter and leader, you may be called on to deliver bad news. If your audience sees the glass as half empty, you have every right – even an obligation – to help them see it as half full.”  

I looked on Pubmed and found a pair of articles from 2011 in the Canadian Veterinary Journal by Myrna Milani on Half-empty and half-full communication – one in October about the client and one in December about the practitioner. There also is a definitive 27-page article with 320 references by David Hecht in the September 2013 issue of Experimental Neurobiology about The neural basis of optimism and pessimism.

Update on September 19, 2018

Fifteen years ago there was a magazine article by Craig R. M. McKenzie and Jonathan D. Nelson titled What a speaker’s choice of frame reveals: reference points, frame selection, and framing effects that appeared in the Psychonomic Bulletin and Review for 2003, on pages 596 to 602, vol. 10 no. 3. Their abstract began [percentages added by me]:

“Framing effects are well established: Listeners’ preferences depend on how outcomes are described to them, or framed. Less well understood is what determines how speakers choose frames. Two experiments revealed that reference points systematically influenced speakers’ choices between logically equivalent frames. For example, [88% of] speakers tended to describe a 4-ounce cup filled to the 2-ounce line as half full if it was previously empty but [only 31% described it as half full or instead 69%] described it as half empty if it was previously full.”

They also looked at glasses one-quarter or three-quarters full, with the results shown above.