The ‘Fractionable Autism Triad’: A Review of Evidence from Behavioural, Genetic, Cognitive and Neural Research

  title={The ‘Fractionable Autism Triad’: A Review of Evidence from Behavioural, Genetic, Cognitive and Neural Research},
  author={Francesca Happ{\'e} and Angelica Ronald},
  journal={Neuropsychology Review},
Autism is diagnosed on the basis of a triad of impairments in social interaction, communication, and flexible imaginative functions (with restricted and repetitive behaviors and interests; RRBIs). There has been a strong presumption that these different features of the syndrome are strongly intertwined and proceed from a common cause at the genetic, cognitive and neural levels. In this review we examine evidence for an alternative approach, considering the triad as largely ‘fractionable’. We… 

Social and non-social autism symptoms and trait domains are genetically dissociable

A genome-wide association study of systemising finds 3 loci associated with systemising and shows that this trait has no significant genetic correlations to social phenotypic measures, demonstrating that the social and non-social aspects of autism are genetically distinct.

The Quantitative Nature of Autistic Social Impairment

A recent body of research in genetics and epidemiology is presented to examine a dimensional reconceptualization of autistic social impairment—as manifested in clinical autistic syndromes, the broader autism phenotype, and normal variation in the general population.

Exploring ‘The autisms’ at a cognitive level

This study aimed to determine whether three widely acknowledged cognitive abnormalities (Theory of Mind impairment, Executive Function (EF) impairment, and the presence of a Local Processing Bias (LB) are universal and fractionable in autism, and whether the relationship between cognition and behavior is dependent on the method of behavioral assessment.

Social and non-social autism symptoms and trait domains are genetically dissociable

It is demonstrated that systemising is heritable and genetically correlated with autism, and strongly suggest that the two core domains of autism are genetically dissociable, and point at how to fractionate the genetics of autism.

Restricted and repetitive behaviors in autism spectrum disorders: a review of research in the last decade.

Evidence suggests that the authors will learn best from the last decade of research by taking a developmental perspective, by directing future research toward subtypes of RRBs, and by implementing early intervention targeted to improve RRBs before these behaviors become entrenched.

Empathizing, systemizing, and autistic traits: latent structure in individuals with autism, their parents, and general population controls.

Factor analyses conducted to assess whether the latent structure of empathizing, systemizing, and autistic traits differs across samples with a high (individuals on the spectrum), medium (first-degree relatives) or low (general population controls) genetic vulnerability to autism suggest a similar latent structure irrespective of genetic vulnerability.

Psychological models of autism: An overview

This chapter provides an overview of the major theoretical accounts of autism, especially the theory of mind hypothesis, the executive dysfunction hypothesis, and weak central coherence theory, each of which has aimed to explain autism in terms of a single underlying cognitive atypicality.

Executive functioning theory and autism

The triad of characteristics that defines the autistic disorder includes the following: social and communication impairments, and restricted, stereotypical patterns of behavior and interests

Behavioural, Biopsychosocial, and Cognitive Models of Autism Spectrum Disorders

Autism spectrum disorder (ASD) comprises a range of developmental disorders including autistic disorder, Asperger’s disorder, and pervasive developmental disorder not otherwise specified/atypical

The association between theory of mind, executive function, and the symptoms of autism spectrum disorder

It is found that ToM ability was associated with both social communication symptoms and RRBs and EF was a correlate of ToM but had no direct association with parent‐reported symptom expression.



Research review: What is the association between the social-communication element of autism and repetitive interests, behaviours and activities?

  • W. MandyD. Skuse
  • Psychology
    Journal of child psychology and psychiatry, and allied disciplines
  • 2008
The approach suggested that the correlation between social-communication impairments and RIBAs has been exaggerated in the current consensus about the autism syndrome, and that these aspects of autism may well share largely independent underlying causes.

Cognition in autism: one deficit or many?

  • F. Happé
  • Psychology
    Novartis Foundation symposium
  • 2003
The aim of this paper is to provoke discussion concerning the nature of the cognitive impairments that characterize autism, and to suggest that searching for the biological bases of specific social and non-social deficits may be more profitable than searching forThe aetiology of autism per se.

Symptom domains in autism and related conditions: evidence for familiality.

The features identified as familial replicate the combined set suggested in earlier, smaller studies and extend to related conditions of milder severity than autism and appear to be independent.

Genetic heterogeneity between the three components of the autism spectrum: a twin study.

The results suggest the triad of impairments that define autism spectrum disorders is heterogeneous genetically, and molecular genetic research examining the three aspects separately may identify different causal pathways for the three components.

Familial symptom domains in monozygotic siblings with autism

Whether there are specific features of autism that show decreased variance within 16 families with monozygotic siblings concordant for autism is examined to provide more homogeneous samples for genetic analysis and strengthen the power to detect the specific genes involved in autism.

Social and Nonsocial Factors in the Childhood Autism Rating Scale

The generation of factor-based scales may provide information on the nature of the individual differences that are thought to be present among children with autism and increase the sensitivity of the CARS for identifying younger and/or higher functioning individuals within the PDD spectrum.

Reciprocal Social Behavior in Children With and Without Pervasive Developmental Disorders

Assessments of RSB on a continuous scale may be useful clinically for characterizing the behavior of children whose social deficits fall below the threshold for a full diagnosis of autism and may also be useful in geneticlinkage studies of autistic spectrum disorders.

Investigating the structure of the restricted, repetitive behaviours and interests domain of autism.

Evidence is provided for the heterogeneity of the RRBI domain of the ADI-R in terms of both clinical presentation and other correlates, which seems to be under familial (presumably genetic) control, while RSMB appears to simply reflect variation in developmental level.

The factor structure of autistic traits.

Future studies of the association between genetic/neurobiologic markers and autistic symptomatology may be enhanced by approaches which consider autistic symptoms as quantitative traits, and which are informed by ongoing research on the development and phenomenology of core deficiencies in reciprocal social behavior.

Exploring the cognitive phenotype of autism: weak "central coherence" in parents and siblings of children with autism: I. Experimental tests.

Results indicated that fathers of boys with autism, as a group, showed piecemeal processing across four tests of central coherence, raising the possibility that the broader autism phenotype may include a "cognitive style" that can confer information-processing advantages.