"An individual whose conscious awareness is such that a sound becomes fused with a sense of color and taste; for whom each fleeting impression engenders a vivid, inextinguishable image; for whom words have quite different meanings than they do for us—such a person cannot mature in the same way others do, nor will his inner world, his life history tend to be like others'."
Luria, A. R. & Solotaroff, Lynn (translator) (1968) The mind of a mnemonist: a little book about a vast memory. Jonathan Cape.
[This book is a case study of Solomon Shereshevskii, whose name is given as “S” in this book. Shereshevskii was a Russian Jewish journalist and mnemonist synaesthete active in 1920s (try saying that fast!). The author’s name is sometimes spelt Aleksandr Luriia]
It appears that the supposedly great Soviet neuropsychologist Aleaxander Luria took the view that synaesthesia necessarily makes synaesthetes in some way impaired in development or subnormal, a view which is not generally held today by synesthesia researchers, a view which I imagine most synaesthetes would object to and also a view which is at odds with the fact that the world of science and psychology has displayed little awareness of how common synaesthesia actually is, presumably because synaesthetes do not generally present with disability or disorder related to their synaesthesia, and thus do not draw attention to their synaesthesia.
So, how did Luria, a clinician and writer apparently held in great regard by many Western contemporary writers and researchers in the area of neuropsychology, make such a monumental blunder? I think the great Luria lacked some very basic skills in critical thinking and statistical reasoning, skills which ordinary people without careers in science or medicine need to have and apply in their everyday lives, let alone researchers and doctors. What was Luria's mistake? I think he failed to reflect upon the potential biasing influence of his sampling method. What sample did Luria take? He took a sample of one synaesthete from the entire population of synesthetes, and he chose to write about only the one synaesthete person who he had sampled and tested and examined and gotten to know, ignoring the rest of the synaesthetes who were potentially out there in the world unexamined, unidentified and unknown by Luria. One could stretch the definition of good scientific research practice by counter-arguing that it is not unknown for scientific studies of single cases to be published in science or medical journals, so it isn't necessarily a bad thing to write single case studies. I'd reply that it is a bad thing to take the sample in a potentially biasing manner, and then hold up the result of the study as in any way representative of the rest of the potential group of subjects who have the same characteristic. How was Luria's sampling method biased? It was hugely biased, because "S" the Jewish mnemonist journalist synaesthete did not come to the attention of Luria on the basis of his synaesthesia alone. S was not selected for attention or study by Luria as a synaesthete representative of all synaesthetes in an organized study of synaesthesia. As I recall the text of the Luria's book The Mind of a Mnemonist (please correct me if I am wrong), S came to the attention of Luria when S's employer almost by accident noticed that S was using an extraordinary memory ability in his ordinary working day, and then the employer contacted Luria about S. It's very obvious that this is not the normal procedure for recruiting study subjects!
I am sure that there are many people in the worlds of science and memory sport who might wonder whether S's synaesthesia was just an interesting feature of his mind found coincidentally in a mind that had also been affected by training in long-established and widely-known memory techniques. S was selected for study by Luria because of his extraordinary memory. Perhaps his synaesthesia was not as important to this ability as some have claimed, but was just found by coincidence. It is true that synaesthesia is now known to be a fairly common mental trait, possibly as common as a feature of 12% of the population, so there's a good chance that any person randomly chosen off the street will experience some type of synaesthesia. But on the other hand, there have been a number of studies and case studies that have found an association between superior memory and synaesthesia, so the question of the relationship between synaesthesia and memory is a live one, and an interesting one.
I think that Luria's characterization of S as in some way impaired or disabled lacks evidence and is questionable, but let's just take Luria's depiction of S at face value, and then ask whether we can be sure that the supposed impairment of S as due to his synaesthesia and not some other factor. We can't be sure at all, because S, like all synaesthetes had other characteristics besides synaesthesia that might have altered his life or the way he was allowed to live his life. I believe he was Jewish and I suspect that Russia has a history of anti-Semitism. He was also a mnemonist, in that he at one time did a stage show based on his memory feats. I believe that these days, (with the exception of Daniel Tammet), mnemonists are understood to be psychologically pretty-much normal people who have chosen to train themselves (there are no institutions that offer such training) in memory techniques. I don't think there are many people who bother to do this, as memory sport and mnemonist performances are not big business and offer little obvious financial or social reward. I hope that memory sport competitiors and present-day mnemonists will not be offended by my assertion that it is a pretty unusual thing to wish to be a mnemonist and to devote the time and effort required to becoming adept and successful in memory techniques. Such people are necessarily autodidacts who are motivated by things in life other than wealth, and are willing to sacrifice a large chunk of their life to cultivating a skill that offers little financial reward, to the possible exclusion of more personally useful and lucrative activities. Such people are certianly unusual. You could call them nerds, outsiders, a bit autistic, or maybe too smart or too competitive for their own good. Maybe they are wealthy people out to prove a point about the superiority of their own minds. I have no idea, as I have no connection or personal experience of memory sport. It is certainly an unusual idea to wish to apply the structure of sport to mental processes, but not a bad idea, in my opinion. One could certainly argue that if Luria studied a synaesthete mnemonist and found him to be a bit odd, the reason for this was that only a person who was a bit odd or socially disadvantaged in some way would be bothered with the training required to become a mnemonist, and that the oddness motivated the training which was the basis of the extreme memory ability, while the synaesthesia was unrelated to all of these things. Luria should have gone looking for other synaesthetes to study, using unbiased sampling methods, to see whether they were also odd or had incredible memories or were in any way distinguishable from non-synaesthetes. But I don't think he did. As they say "Too much like hard work".