Reading the script to Will Eno's play The Realistic Joneses can leave you riddled with anxiety.

The story of two couples with the same name who live in an ordinary American town and behind a curtain of words that thwart any semblance of mutual understanding, it contains clever, deceptively simple koans: "It must be so quiet when it isn't noisy," "Sometimes, I forget stuff. On the other hand, sometimes I remember stuff."

While Eno isn't entirely delighted to know that I've been put on edge, he's glad I had a reaction:"I’m glad, whatever the case, that you got some authentic feeling from it."  

It turns out that words have been on his mind more than usual, even by the standards of a playwright. Eno, a Brooklyn resident and the author of The Open House and the Pulitzer-finalist Thom Pain (based on nothing) has been reading a book about children's brain development now that their daughter is 18 months old.

"The simple, huge irony of the fact is that our right brain is emotional stuff, intuitive stuff, but words are over on the other side," he said. "It never occurred to me that the word part of the brain is a separate anatomical structure from the part where the feeling goes on. It was interesting and problematic to me."

How so? This must be the precise type of thing he thinks about all day, no?

"Without really thinking about it, we assume that words are going to solve an emotional crisis, that words would be applicable," he said. Feelings, as discharges of the brain, have " already changed into something else just by nature of going into words, and someone has to hear it and respond in words — with either help or interference from the emotional part.”

It's loosely analogous to the difference between reading a script and witnessing trained actors breathe life into words on the page. Having run on Broadway with actors like Michael C. Hall (Lazarus, Dexter) and Marisa Tomei (Marie and Bruce, Empire), The Realistic Joneses has been blessed with talent that can make Beckett-esque dialogue appear warm. An exchange like "I was just thinking about..."/"No, you said it," might not work in just anyone's hands.

(And as it turns out, the director of the Broadway production of The Realistic Joneses was none other than Sam Gold, who went on to win a Best Director Tony for Fun Home, which will appear at A.C.T.'s next-door-neighbor, The Curran, in January.)

"The play has been around, it's gotten nice reviews in a number of productions," Eno said. "Often, reviewers would say, 'This is the type of play that would be terrible in the wrong hands.' It does sort of make me wonder, what plays are good in the wrong hands? The nature of the thing is that you write it, and actors have to do it. All that said, I think these guys are doing a pretty snappy job."

It's hardly a bloodless devotion to words qua words that animates this play, either. Eno feels genuine compassion for his characters, whose affliction is more the human condition than the modern condition of suburban alienation — "I think of thee characters as doing a pretty good job at an impossible task," he said.

And it's funny. So funny, in fact, that some people have been surprised.

"We had a dress rehearsal for the Broadway production, and one of the producers, who was engaged [in her work] came up to me and said, ‘Who knew you were funny?’ I was amused that she just wanted to produce a play about people who died."

The Realistic Joneses, through April 3 at the American Conservatory Theater, 415 Geary St. 415-749-2228 or act-sf.org.