The prodigious savant Daniel Tammet was just profiled on 60 Minutes, sparking a provocative email from my brainy and combative step-uncle Stan; he wants to know how savant syndrome fits into, or conflicts with, my developing understanding of talent.
Tammet is as rare as it gets: there are only 50 or so prodigious (truly exceptional) savants out there. But there are thousands more savants who are highly-impressive in one way or another, and as a group they can offer us enormous insight into the workings of the brain and the nature of intelligence.
The lessons are surprising. At first blush, one might assume that savants are proof that biology trumps effort: everyone's brain has a slightly different circuitry and will perform accordingly; savants are at one extreme end of the spectrum, with very strange wiring that confers amazing ability.
The truth is a lot more interesting. Here's a Savant FAQ, informed by the work of Darold Treffert, one of the world's leading savant authorities.
What is savant syndrome?
Savant syndrome is the presence of unusual intellectual and/or artistic abilities in otherwise impaired individuals. It is seen in an estimated 1 in 10 persons with autism, AND in roughly 1 in 1000 persons with other mental impairments, including developmental disability, mental retardation, and other central nervous system injuries or diseases. Savantism occurs in many more males than females -- a 6:1 ratio.
Is it always present from birth?
No, and that turns out to have very important implications. Says Treffert: "Savant syndrome can be congenital, or it can be acquired following brain injury or disease later in infancy, childhood, or adult life. Recent reports of savant-type abilities emerging in previously healthy elderly persons with fronto-temporal dementia are particularly intriguing."
What are the specific abilities displayed by savants?
As a rule, they are right-hemisphere skills: music, art, math, spatial dexterity and calendar calculation -- what Treffert calls an "intriguingly narrow range of special abilities" made possible by a spectacular deployment of mechanical, or concrete (also called "implicit") memory.
What's the underlying cause?
No current theory can account for all the cases of savant syndrome, but the most prominent theory that plausibly covers most cases is an injury to the left part of the brain (in the womb, infancy, childhood or adulthood) which sparks a dramatic compensation by the right brain.
--- Treffert elaborates: "Some savants, because of prenatal, perinatal or postnatal central nervous system damage, from a variety of genetic, injury or disease processes have substituted right brain capacity in a compensatory manner for left brain dysfunction and limitation. Simultaneously, because of those same injurious factors, these savants have come to rely on more primitive cortico-striatal (procedural or habit) memory rather than higher level cortico-limbic (semantic or declarative) memory. This combination of right brain skills coupled with procedural memory produces the constellation of abilities and traits that is savant syndrome."
But how can a brain injury give someone exceptional abilities?
We know from centuries of medical history, including the emergence of various medical oddities over the years, that certain components in every brain are equipped with incredible technical capabilities -- capabilities normally suppressed by other components so that the brain can do its main job, which is to balance out function and help a person lead a normal life. For example, in my book The Forgetting, I discuss the famous Russian patient S. who literally remembered every detail he came across in his entire life. He could recite verbatim conversations or random number lists decades after the fact. Sounds cool,bBut this was actually a huge liability -- remembering every detail makes it impossible to form intelligent summaries of details, which is the basis of all intelligent thought and communication. The ability to forget -- get rid of sensory detail -- turns out to be just as important in the brain as the ability to form new memories.
Similarly, savants become unhinged from the usual cerebral checks and balances. Treffert explains: "'Weak central coherence' theory (WCC) [is the ability/disability of] focusing on details rather than the whole....Not being distracted by more global patterns, the savant can focus on a single item or skill and perfect it." (He cites Frith & Happe, 1994).
Like a car spinning around and around because its steering wheel is stuck in the right-turn position, savants' severe brain injuries push them to focus all their time and energy away from the wide burden of social function and into one or more very narrow skills.
What are the lessons for normal functioning brains?
1. Savants don't have amazing abilities -- they acquire them.
Savant brain injuries, whether in the womb or much later on, don't instantly bestow people with amazing powers -- rather, they set loose normally restricted brain mechanisms which allow that person to hyper-focus on a certain skill set in a way that normal functioning minds cannot. Through their disability, they are able to develop amazing skill. As Daniel Coyle recently wrote in the NYT: "Savants' true expertise, the research suggests, is in their ability to practice obsessively, even when it doesn't look as if they're practicing."
2. We can acquire them too.
Although it's a far more cumbersome process, anyone with a normal functional brain can also develop advanced -- and even extraordinary -- skills. Ericsson, Dweck et al have shown some paths to get there, and Treffert argues that we may be able to develop further training methods based on what we're learning from savant brains. "Does some Rain Man ability — savant-like skill and capacity — exist in each of us?" posits Treffert. "Probably so. [The] more primitive memory circuitry, and right brain capacity, both still exist in each of us. However because of their inherent, utilitarian usefulness we have generally come to rely more heavily on left (dominant) hemisphere functions such as language, logical & sequential thinking, for example, than on right (non-dominant) hemisphere skills. Likewise in our day to day functioning we have come to generally use and depend upon semantic or declarative memory much more than using our more primitive, and less facile, procedural or habit memory capabilities. The question becomes then, is it possible to tap and use those still existent, but less frequently used, capacities and circuits, with some of their savant-like characteristics, in those of us more wedded to left brain capacity and higher level memory? ... ...I am convinced there is."