The quest for autism ’ s causes , and what it reveals about all of us
By Emily Willingham
The more researchers look , the more multifaceted the risk factors appear — and the more we learn about how the brain works and develops
As alarm grew over autism prevalence at the turn of this century , there was much public talk of a growing “ epidemic .” That language has since softened , and it is now clear that many autistic people were there all along , their condition unrecognized until relatively recently .
But what is the cause ? The emerging narrative today is that there is no single cause — rather , multiple factors , roughly sorted into the categories of genetics and environment , work together in complex ways . Because of this complexity and the
hundreds of
gene variants that have been
implicated , developing human brains may follow many possible paths to arrive at a place on the autism spectrum .
As clinicians view it , autism involves communication deficits and formulaic , repetitive behaviors that present obstacles to establishing conventional relationships . The soft borders of that definition — where does communication difficulty cross over into communication deficit ? — suggest blurred margins between people who are diagnosed with autism and those who approach , but never quite cross , the line into diagnostic territory .
Those who do have diagnoses display behaviors on a continuum of intensity . Their use of spoken language ranges from not speaking at all to being hyperverbal . They can have a unique interest in the finer details of window blinds or an intense but more socially tolerated fascination with dinosaurs . As with many human behaviors , each feature exists on a spectrum , and these spectra blend in a person to create what clinicians call autism .
By pinpointing risk-associated genes and uncovering their roles , studying the roots of autism also is providing new insights into the development of all human brains , autistic or not . Here is a taste of what we now know , and what we don ’ t , about autism ’ s causes — and what that search is teaching us about everybody ’ s neurology .
They know it when they see it Despite the many and varied threads that may interweave to cause autism , the condition is largely identifiable . What clinicians are really saying when they diagnose autism , says James McPartland , a
46 Accessibilty for All To Table of Contents