To me it would have seemed more natural to have written ‘were completely blinded’.
You are right. Dan Ariely’s sentence does not seem natural regardless of the punctuation. The answer to your question has to do with what reading is – well, what readers do. And it turns out that neuroscientists now know one very interesting thing about reading which explains exactly how Dan’s sentence is problematic : reading uses the same parts of your brain that are used in speech production and listening, notably Broca’s area and Wernicke’s area, and uses them in the same way.
It makes sense that the same parts of your brain are used for reading, listening, and speech, because you are using the same vocabulary and grammar for all three activities. But what’s interesting is that reusing the same parts of your brain means reading, listening, and speaking are mostly the same thing. When you read, you can meaningfully say you are speaking the words to yourself and listening to them in order to make sense of them. The observation that we sometimes “hear” a text in our own voice as we read it is not an illusion, or even a side effect : it is fundamental to how we do language.
Not only that, but reading, listening, and speaking all light up other parts of your brain which deal with memory and imagination, and they all do it in the same way. As you read, you create mental simulations of the narrative that involve multiple senses and include creative imaginings of things which are not even mentioned. Whether you speak of cheese, hear of cheese, or read about cheese, you see, smell, and taste the cheese. You even see where it is – perhaps on a cheese-board, or in your hand – regardless of whether that detail is in the narrative. As you read a text, you are continually adding to your mental simulation, and this helps you notice when something does not make sense.
When a text does not follow the same rules as speech, the result is confusion : it seems wrong because reading is a form of listening and of speech. You stumble over the text as you would if you were speaking the words aloud or listening to them.
This is what happened when you read Dan Ariely’s sentence. You heard
Zoe and the other kids to whom I offered the same deal was completely blinded by
and by the time you got to was you had already built up a mental simulation of the first part of the sentence with some kids (plural) in it. Your brain had trouble making was (singular) fit with this mental picture. To describe this situation we say there is an error in subject-verb agreement.
I agree that Dan Ariely intended the commas to delimit a parenthesis, a remark which you insert into the middle of a sentence as if you are interrupting yourself. A parenthesis contributes to the meaning of the sentence but interrupts and stands outside its syntax. Wikipedia derives the word from the Greek παρένθεσις, meaning “to place alongside of”.
and the other kids to whom I offered the same deal
will work as a parenthesis if you hear it like one when you speak it to yourself. The trouble is that it also happens to work within the syntax of the sentence, leading you down the garden path until you encounter the word was. Commas are not always enough to cue a parenthesis. Dan should have used round brackets (parentheses) – or even dashes – to guide the reader to treat the interruption as an interruption.
2009 Cook/Dehaene Scientific American “Your Brain on Books : Neuroscientist Stanislas Dehaene explains his quest to understand how the mind makes sense of written language”.
2011 Stafford/Blackburne “What happens in the brain when you read : A Conversation with Livia Blackburne”.
2012 Bergen Louder Than Words : The New Science of How the Mind Makes Meaning.
2012 Paul The New York Times “Your Brain on Fiction”.
2013 “scicurious” Neurotic Physiology (blog) “Silent reading isn’t so silent, at least, not to your brain”.
2013 Wikipedia “Broca’s area”.
2013 Wikipedia “Wernicke’s area”.
2013 Wikipedia “Parenthesis (rhetoric)”.