Essentially Badcock argues that autism and psychosis, particularly schizophrenia, exist on a continuum. The autistic person and the schizophrenic contrast broadly in behavioral and organic ways. Some of them include trouble gauging the attentive gazes of others vs. delusions of being watched, inattention to others' voices vs. hallucinating voices, difficulties in accounting for the different intentions of others vs. delusions of persecution or being the object of others' sexual interest, an inability to share the object of attention with others vs. delusions of conspiracy, an extreme literalness and inability to lie vs. delusional self-deception, an early onset of autism vs. developing schizophrenia as an adult, acute visual and spatial skills vs. difficulty in visual reasoning and deficits in visual acuity, and brains with local areas over-connected with a neural network but an underdevelopment of global brain connections vs. the opposite in a schizophrenic brain. For Badcock `s argument, it seems one final contrast is the most important. The autistic has trouble modeling the minds of others. The schizophrenic obsessively models the minds and intents of others with frequent delusions of conspiracy.

Badcock doesn't envisage a single brain system with autism and schizophrenia as its maladapted extremes. Badcock proposes two systems at work in the brain. One is a system devoted to things with its most extreme manifestation being in autistics. (It's not for nothing that autism's mildest form, Asperger's Syndrome, is known as the "engineer's disease".) The second is a system devoted to social interactions with people. Badcock dubs this system "mentalism" but with none of the psychic connotations sometimes associated with that word - though Badcock argues that there are savants, "hypermentalists", in this area just as autism produces savants. Humans, however, are generally evolved to deal with others of their species and not arithmetic, so the savant of mentalism does not seem as abnormal as the famous Rain Man. They may hide behind the reputation of a famous politician, artist, poet, con man, or prophet.

Badcock links these two systems with the two sexes and the links are what you would expect. The male mind is associated with thing-thought. Females are associated with mentalism.

Genes play their role in mediating these two systems. Badcock acknowledges his debt to Bill Hamilton's work. It was later popularized by Richard Dawkins under the "selfish gene" theory. What Hamilton argued is that natural selection works on individual genes, not organisms. Organisms are just a vehicle for a gene to perpetuate themselves into the next generation. In Badcock's view, autism and schizophrenia are the results of a war conducted by genes in the developing brain, specifically paternal and maternal genes.

This war conducted in the womb represents a couple of competing interests. Maternal genes, to curb the dangers and reduce the load of pregnancy and caring for young children, favor lower birth weights, less aggression, less appetite, a less invasive placenta. The mother's genes promote mentalism. Mothers have developed, to control their children - and the mother always knows if they are her children, efficient ways to control her offspring, what Badcock memorably dubs "naming, blaming, and shaming". Carrying a child to term and tending them after birth obviously requires much less for a man - and there is always the potential for a man wasting resources on a cuckoo.

Badcock details how imprinted genes - genes which are not expressed if they are inherited from a particular sex - and oddities in the inheritance of sexual chromosomes derails normal brain development and opens the way for susceptibility for some of the environmental injuries suspected of causing autism and schizophrenia.
Badcock provides some fascinating evidence for his theory with a dense amount of footnotes and bibliography. I doubt this book is intended solely for a scientific audience. Given the number of articles written by Badcock and his collaborator Bernard Crespi which show up in the latter, Badcock seems to have put his theory out to academia, and, I suspect, has proposed more falsifications of it than show up here. However, the book is fairly readable, if dense, and fascinating. His basic theory seems plausible to this layman.

Badcock does go off on some fascinating tangents: the place of "hypermentalism" in the development of religion and magic as opposed to the more autistic content of some superstitions, autistic and hypermental savants in detective fiction, how chimps compare to humans in monitoring gazes, the civilizational benefits of each type of abnormality, the possibility that what we call schizophrenia is just the extreme form of the hypermental mind with other psychosis resulting from the same causes, and the "animal mind" of the autistic. While interesting, his notion that certain human geniuses - Isaac Newton and Sigmund Freud being the case studies - are the product of both autism and hypermentalism was less well developed and, therefore, less convincing.

Anybody wanting to read a serious book on autism or brain development or genetically based psychology will want to read this book. ( )