The prenatal autistic imprinting hypothesis: developmental maladaptation to the environmental changes between womb and the social world

Abstract 

Although the importance of biological and genetic aspects of the etiology is well recognized, the pathological process of autism still remains to be elucidated. In contrast to a qualitative dichotomy concept, a dimensional perspective that places the autistic traits as quantitative extremes can easily explain the diversity and subtlety of the clinical features. In a dimensional (quantitative continuum) condition, no single qualitative process can distinguish the extremes from normal variations. In addition, the traditional view, which regards autism as a hypo-reproductive disease with a strong genetic contribution, cannot interpret the recent worldwide prevalence of autism. From a novel viewpoint, we have proposed ‘the prenatal autistic imprinting hypothesis’ in which autism is regarded as an inevitable consequence of human social evolution in both past and future. Postulated primary phenotypes are closely associated with the autistic savant skills and the autistic adherent temperament, and might increase the chance of specific prenatal experiences, named ‘autistic imprinting’. An earlier prenatal brain growth and an earlier establishment of a type of consciousness may be critical for the imprinting process. A postnatal autistic social maladaptation may be a mere outcome of the putative intrauterine behavioral adaptation in individuals with the primary phenotypes. Both an autistic manner of thinking, which is referred to as ‘visual thinking’, and the prenatal early development of visual cortical architectures may play a key role in the autistic imprinting process.