AUTISMANDTHETECHNICALMIND

1、A U T I S M A N D T H E T E C H N I C A L M I N D Childre n of scie ntists and engin eers may in herit genes that not only confer in tellectual tale nts but also p redis pose them to autism By Simon Baron-Cohe n IN 1997 MY COLLEAGUE SALLY WHEELWRIGHT AND I CONDUCTED A STUDY INVOLVING nearly 2,000 fa

2、milies in the U.K. We included about half these families because they had at least one child with autism, a devel opmen tal con diti onin which in dividuals have di culty com muni cati ng and in teract ing with others and dis play obsessive behaviors. The other families had childre n with a diag no

3、sis of Tourette s syn drome, Down syn drome or Ian guage delays but not autism. We asked parents in each family a simple question: What was their job? Many mothers had not worked outside the home, so we could not use their data, but the results from fathers were in trigu ing: 12.5 p erce nt of fathe

4、rs of 74 Scien tific America n, November 2012 childre n with autism were engin eers, comp ared with only 5 p erce nt of fathers of childre n without autism. Likewise, 21.2 percent of gran dfathers of childre n with autism had bee n engin eers, comp ared with only 2.5 percent of grandfathers of child

5、ren without autism. The pattern appeared on both sides of the family. Wome n who had a child with autism were more likely to have a father who had bee n an engin eer and they were more likely to have married some one whose father had bee n an engin eer. Coin cide nee? I think not. A possible explana

6、tion involves a phenomenon known as assortative mating, which usually means “like pairs with like. ” I first encountered the concept in an undergraduate statistics tutorial at the University of Oxford in 1978, when my tutor told me (perhaps to make statistics a little more lively) that whom you have

7、 sex with is n ot ran dom. When I asked her to elaborate, she gave me the exa mple of height: tall people tend to mate with tall peop le, and short people tend to mate with short people. Height is not the only characteristic that consciously and subconsciously in flue nces partner select ion age is

8、ano ther exa mple, as are person ality typ es. Now, more tha n 30 years later, my colleagues and I are testing whether assortative mating explains why autism persists in the general population. When people with technical minds such as engineers, scie ntists, compu ter p rogrammers and mathematicia n

9、s marry other tech ni cal-m in ded in dividuals, or their sons and daughters do, do they pass down linked groups of genes that not only endow their p roge ny with useful cog nitive tale nts but also in crease their childre n s cha nces of devel oping autism? SYStTEM CHECK I bega n study ing autism i

10、n the 1980s. By the n, the p sychoge nic theory of autism which argued that emoti on ally dis in terested mothers caused their childre n s autismhad bee n soun dly refuted. Michael Rutter, now at King s College London, and others had begun to study autism in twins and had show n that autism was high

11、ly heritable. Gen etics, not parenting, was at work. Today researchers know that an ide ntical twin of some one with autism is around 70 times more likely to devel op autism, too, comp ared with an un related in dividual. Although researchers have un covered associati ons betwee n sp ecific genes an

12、d autism, no one has ide ntified a group of genes that reliably p redicts who will deve lop the con diti on. The gen etics of autism are far more comp lex than that. What I have bee n in terested in un dersta nding, however, is how genes for autism survive in the first place. After all, autism limit

13、s one s abilities to read others emotions and to form relationships, which in turn may reduce one s chances of having children and passing on one s gen es. One possibility is that the genes responsible for autism persist, generation after generation, because they are co-i nherited with genes un derl

14、y ing certa in cog nitive tale nts com mon to both people with autism and tech nical-m in ded people whom some might call geeks. In esse nee, some geeks may be carriers of genes for autism: in their own life, they do not dem on strate any sig ns of severe autism, but whe n they p air up and have kid

15、s, their childre n may get a double dose of autism genes and traits. In this way, assortative mating between technical-minded people might spread autism gen es. Because “ geek” is not the most scientific term, and for some may be pejorative, I needed to formulate a more p recise defi niti on of the

16、cog nitive tale nts shared by tech ni cal-m in ded people and people with autism. In the early 2000s Wheelwright and I surveyed nearly 100 families with at least one child with autism and asked another basic question: What was their child s obsession? We received a diverse array of answers that incl

17、uded memorizing train timetables, learning the names of every member of a category (for instanee, dinosaurs, cars, mushrooms), putting electrical switches around the house into p articular po siti ons, and running the water in the sink and rushi ng outside to see it flow ing out of the drainpipe. On

18、 the surface, these very differe nt behaviors seem to share little, but they are all exa mples of systemiz in g. I defi ne systemiz ing as the drive to an alyze or con struct a system a mecha ni cal System (such as a car or computer), a natural system (nutrition) or an abstract system (mathematics).

19、 Systemiz ing is not restricted to tech no logy, engin eeri ng and math. Some systems are eve n social, such as a bus in ess, and some in volve artistic pu rsuits, such as classical dance or piano. All systems follow rules. When you systemize, you ide ntify the rules that gover n the system so you c

20、an p redict how that system works. This fun dame ntal drive to systemize might exp lain why people with autism love rep etiti on and resist unexp ected cha nges. Collaborat ing once aga in with Wheelwright, who is now at the Uni versity of Southa mpton in En gla nd, I put the link betwee n systemiz

21、ing and autism to the test. We found that childre n with Asperger s syndrome a form of autism with no Ianguage or intelligenee impairments out performed older, typ ically deve loping childre n on a test of un dersta nding mecha ni cs. We also found that on average, adults and childre n with Asp erge

22、r s scored higher on self-re port and paren t-re port measures of systemiz ing. Fin ally, we found that people with Asp erger s scored higher on a test of atte nti on to detail. Atte nti on to detail is a p rerequisite for good systemiz in g. It makes a world of differe nee whe n trying to un dersta

23、 nd a system if you spot the small details or if you mistake one tiny variable in the system. (Imagine getting one digit wrong in a math calculati on.) When we gave the test of atte nti on to detail to paren ts, both the mothers and fathers of children with autism were also faster and more accurate

24、than those of typically developing childre n. Engin eers aren t the only tech ni cal-m in ded people who might harbor autism gen es. In 1998 Wheelwright and I found that math stude nts at the Uni versity of Cambridge were nine times more likely tha n huma nities stude nts to report havi ng a formal

25、diag no sis of autism, in cludi ng Asp erger s, which will be folded into the broader “ autism spectrum disorder ” in the newest edition of psychiatry s guidebook, the DSM-5. Whereas only 0.2 percent of students in the humanities had autism, a figure not so different from the rate of autism reported

26、 in the wider population at the time, 1.8 p erce nt of the math stude nts had it. We also found that the sibli ngs of mathematicia ns were five times more likely to have autism, comp ared with the sibli ngs of those in the huma nities. In ano ther test of the link betwee n autism and math, Wheelwrig

27、ht and I devel oped a metric for measuring traits associated with autism in the general population, called the Autism Spectrum Quotie nt (AQ). It has 50 items, each rep rese nti ng one such trait. No one scores zero on the test. On average, typ ically devel oping men score 17 out of 50, and typi cal

28、ly devel oping wome n score 15 out of 50. People with autism usually score above 32. We gave the AQ to winners of the British Mathematical Olympi ad. They averaged 21 out of 50. This p atter n suggested that regardless of official diag no ses mathematical tale nt was also lin ked to a higher nu mber

29、 of traits associated with autism. The Silic on V alley Phenomenon One way to test the assortative mati ng theory is to compare couples in which both in dividuals are strong systemizers with coup les who in clude only one stro ng systemizer or none. Two- systemizer coup les may be more likely to hav

30、e a child with autism. My colleagues and I created a Web site where parents can report what they studied in college, their occ up ati ons, and whether or not their childre n have autism ( paren ts). Mean while we are exploring the theory from other an gles. If genes for tech ni cal ap titude are lin

31、 ked to genes for autism, the n autism should be more com mon in p laces around the world where many systemizers live, work and marry places such as Silicon Valley in California, which some people claim has autism rates 10 times higher tha n the average for the gen eral popu lati on. In Ban galore,

32、the Silic on Valley of In dia, local cli ni cia ns have made similar observati ons. Alu mni of the Massachusetts In stitute of Tech no logy have also reported rates of autism 10 times higher tha n average among their childre n. Unfortun ately, no one has yet con ducted detailed and systematic studie

33、s in Silic on V alley, Ban galore or M.I. T., so these acco unts remai n an ecdotal. My colleagues and I, however, have in vestigated the rates of autism in Ein dhove n, the Silic on Valley of the Netherla nds. Royal Phili ps Electr onics has bee n a major empio yer in Ein dhove n since 1891, and IB

34、M has a branch in the city .In deed, some 30 percent of jobs in Ein dhove n are in the IT sector. Ein dhove n is also home to Ein dhove n Uni versity of Tech no logy and High Tech Campus Ein dhove n, the Dutch equivale nt of M.I.T. We comp ared rates of autism in Ein dhove n with rates of autism in

35、two similarly sized cities in the Netherla nds: Utrecht and Haarlem. In 2010 we asked every school in all three cities to count how many childre n among their pup ils had a formal diag no sis of autism. A total of 369 schools took part, p rovidi ng in formatio n on about 62,505 childre n. We found t

36、hat the rate of autism in Ein dhove n was almost three times higher (229 per 10,000) than in Haarlem (84 per 10,000) or Utrecht (57 per 10,000). MALE MINDS In p arallel with test ing the link betwee n autism and systemiz ing, we have bee n exam ining why autism app ears to be so much more com mon am

37、ong boys tha n among girls. In classic autism, the sex ratio is about four boys to every girl. In Asperger s, the sex ratio may be as high as nine boys for every girl. Likewise, strong systemiz ing is much more com mon in men tha n in wome n. In childhood, boys on average show a stronger interest in

38、 mechanical systems (such as toy vehicles) and con struct ional systems (such as Lego). I n adulthood, men are overrep rese nted in STEM subjects (scie nee, tech no logy, engin eeri ng and math) but not in people - cen tered scie nces such as cli ni cal psychology or medicine. We have been investiga

39、ting whether high levels of the hormone testosterone in the fetus, long known to play a role in“ masculinizing ” the developing brain in ani mals, correlate with stro ng systemiz ing and more traits associated with autism. A huma n male fetus p roduces at least twice as much testoster one as a femal

40、e fetus does. To test these ideas, my colleague Bonnie Auyeung of the Cambridge Autism Research Center and I studied 235 pregnant women undergoing amniocentesis a procedure in which a long n eedle samp les the amni otic fluid surr ounding a fetus. We found that the more testoster one surrounding a f

41、etus in the womb, the stronger the children s later interest in systems, the better their atte nti on to detail and the higher their nu mber of traits associated with autism. Researchers in Cambridge, En gla nd, and Denmark are now collaborati ng to test whether childre n who even tually devel op au

42、tism were expo sed to elevated levels of testoster one in the womb. If fetal testostero ne p lays an imp orta nt role in autism, wome n with autism should be esp ecially masculinized in certain ways. Some evidenee suggests that this is true. Girls with autism show “tomboyism ” in their toy - choice preferences. On average, women with autism and their mothers also have an elevated rate of poly cystic ovary syn drome, which is cau