This would come as no surprise to anyone in the medical profession.
In the venerable sitcom M*A*S*H, there was a memorable episode in Season 6. Hawkeye (Alan Alda) and the other doctors had a problem: they were out of morphine, and the hospital
Of course, it worked like a charm, and the patients rested comfortably until the real meds arrived.
The mind - even Nemorino's! - has an amazing ability to bring about drastic changes.
Here's another film reference: remember the Disney animated classic Dumbo? (Ah, the 1940's, when a children's movie could show the hero being so falling-down drunk he was hallucinating. I recently heard that a new live-action remake is in the works. Think maybe that scene will be omitted in 2019?)
Anyway, Dumbo has his own placebo: that black feather. The little fellow with the gigantic ears flies without knowing how he did it. A kindly crow, to bolster his confidence, hands him one of his own feathers, promising that as long as he holds on to that feather, he can fly like a bird and be the star of the circus. The big moment comes when the feather blows away in mid-air, causing Dumbo to plummet like the value of my 401K lately. (But I digress.) Naturally, Dumbo realizes that he can fly, feather or no. Happy ending.
The point is that, ironically, the sugar pills worked. The black feather worked.
And so does Dr. Dulcamara's elixir of love. I'm not sure the rest of the village can expect the same results in the areas of curing asthma, paralysis and diabetes. (I mean, come on - the human body turns alcohol into sugar. Give me a break on that one.) But for Nemorino's agenda, the elixir works right in front of our eyes.
There is a moment in which everything changes in the blink of an eye. Nemorino has chugged his bottole of "love potion" and, in his ill-educated bucolic innocence, believes he can feel it working. Adina happens by, startled to see the pathetic farm-boy acting strangely. Nemorino mis-interprets her attitude, and in response he makes a fateful decision:
He ignores her.
THIS catches the It Girl's attention. This is new. Why isn't he staring at her like an adoring puppy as usual? Now Nemorino gets into the spirit of the thing, "Go ahead, laugh at me", he thinks, "by tomorrow my suffering will be over!"
See what's happening? The illusion of magic is motivating him to behave as if the magic were real. He's exuding confidence. We in the audience understand that this confidence is foolish and that he's just tipsy, but hey - confidence is confidence, and Adina notices.
This forces her to reconsider who Nemorino is and re-evaluate how she feels about him. From this point on, nothing is the same. The irresistible force is going to conquer the immovable object.
And Donizetti lets us hear this sudden personality change in Nemorino's vocal writing. The opening cavatina "Quanto è bella" (sung here by Lawrence Brownlee) is in full "I'm so pathetic" mode. The vocal lines are wistful, full of hopeless longing, completely passive.
By the way, it's sort of cool that librettist Felice Romani's lyrics for this solo eerily predict pop songs from the mid-20th century. If you're of a certain generation, you'll remember Vic Damone and Sammy Davis Jr. singing The more I see you/The more I want you/Somehow this feeling/Just grows and grows. This is a match for Nemorino's Più la vedo, e più mi piace or The more I see her, the more I like her. And when the farm-boy sings about how great she is, then laments that he's incapable of inspiring affection in her, it makes me thing of "The Girl From Ipanema"
Now, compare that with the manifest cockiness exuding from his outburst in :Esulti pur la barbara" (beginning at 3:23 in this clip with Pavarotti and Battle). The vocal writing is resolute, determined and bold. Nemorino's voice repeatedly thrusts upward from dominant to tonic and even higher.
He's a new person. When Adina finally realizes she has feelings for him and they become a couple, even Dulcamara does a double-take, allowing himself a fleeting second to wonder if somehow he stumbled upon The Real Thing. Of course, the moment passes and he's content to celebrate the epiphany that, with a "satisfied customer" in tow, he's sitting on a gold mine.
In short, the comedy is funny because the psychology is true.
Next week I'll survey "The Sons of Dulcamara" and examine other elixir-touting con men of music drama, with an eye toward seeing if the placebo effect is in evidence in any of them.