Male Brain Theory Of Autism Research Articles

No relationship between prenatal or early postnatal androgen exposure and autistic traits: evidence using anogenital distance and penile length measurements at birth and 3months of age.

Autism is more prevalent in males than in females. Hypotheses related to the extreme male brain theory of autism suggest that heightened androgen exposure during early development contributes to autistic traits. Whilst prior research focused mostly on the prenatal period, the current study tests the influences of androgen exposure during both the prenatal and the early postnatal periods on autistic traits during childhood. Anthropometric measures that are putative biomarkers of early androgen exposure were employed. Anogenital distance (AGD) was measured at birth and 3months of age in boys and girls. Penile length at birth and 3months of age was also measured in boys. When the children were 9-13years old, a parent-reported questionnaire (the 10-item children's version of the Autism Spectrum Quotient; AQ-10 Child) was used to assess autistic traits in 97 boys and 110 girls. There were no significant associations between any of the AGD or penile length measures and scores on the AQ-10 Child in boys, girls or the entire sample. The current study provides the first test of whether early measurements of AGD and/or penile length predict subsequent autistic traits. The current findings do not support a relationship between prenatal or early postnatal androgen exposure and autistic traits. The current study augments prior research showing no consistent relationship between early androgen exposure and autistic traits.

Autistic traits, systemising, empathising, and theory of mind in transgender and non-binary adults

BackgroundPrior research examining autistic traits in gender minority adults has reported mixed findings. Most prior studies did not include non-binary individuals. Little is known about the mechanisms shaping autistic traits in gender minority adults. This study examined autistic traits, as well as constructs related to the extreme male brain theory of autism and the mindblindness theory, in transgender and non-binary adults.MethodsAn online survey was conducted to assess autism-related traits in 323 gender minority adults, including 74 transgender men (individuals assigned female at birth and identify as a man), 95 transgender women (individuals assigned male at birth and identify as a woman), 104 non-binary AFAB (individuals assigned female at birth and identify as non-binary), and 50 non-binary AMAB (individuals assigned male at birth and identify as non-binary). Autistic traits, systemising, empathising, and Theory of Mind (ToM) were measured using the Autism Spectrum Quotient (AQ), the short forms of the Systemising Quotient (SQ-Short) and the Empathy Quotient (EQ-Short), the 10-item version of the Empathy Quotient (EQ-10) and the Reading the Mind in the Eyes Test (Eyes Test). Participants’ scores on these measures were compared with previously published scores based on large-scale general population samples including thousands of participants.ResultsOn average, compared with control females in the general population samples, both transgender men and non-binary AFAB scored significantly higher on the AQ and the SQ-Short but scored significantly lower on the EQ-Short, the EQ-10, and the Eyes Test. No clear or consistent group differences emerged when transgender women and non-binary AMAB were compared with control males.LimitationsThe present study does not have a large sample of gender minority adults. It has been argued that the measures employed may not provide a precise assessment of the psychological constructs of interest. The present study has a “non-clinical” sample. However, not all gender minorities have access to or require clinical services, and so a “non-clinical” sample may be more representative of the gender minority community as a whole than samples recruited through clinics.ConclusionsThe current findings suggest a “masculinised” autism-related profile and reduced ToM in transgender men and in non-binary AFAB. These findings might be interpreted to support the extreme male brain theory of autism and the mindblindness theory. Further research is needed to corroborate these findings.

AMBRA1, Autophagy, and the Extreme Male Brain Theory of Autism.

The extreme male brain theory of autism posits that its male bias is mediated by exaggeration of male-biased sex differences in the expression of autism-associated traits found in typical populations. The theory is supported by extensive phenotypic evidence, but no genes have yet been described with properties that fit its predictions. The autophagy-associated gene AMBRA1 represents one of the top genome-wide “hits” in recent GWAS studies of schizophrenia, shows sex-differential expression, and has been linked with autism risk and traits in humans and mice, especially or exclusively among females. We genotyped the AMBRA1 autism-risk SNP in a population of typical humans who were scored for the dimensional expression of autistic and schizotypal traits. Females, but not males, homozygous for the GG genotype showed a significant increase in score for the single trait, the Autism Quotient-Imagination subscale, that exhibits a strong, significant male bias in typical populations. As such, females with this genotype resembled males for this highly sexually dimorphic, autism-associated phenotype. These findings support the extreme male brain hypothesis and indicate that sex-specific genetic effects can mediate aspects of risk for autism.

Testing the Empathizing–Systemizing theory of sex differences and the Extreme Male Brain theory of autism in half a million people

Testing the Empathizing–Systemizing theory of sex differences and the Extreme Male Brain theory of autism in half a million people

Testing the Empathizing–Systemizing theory of sex differences and the Extreme Male Brain theory of autism in half a million people

The Empathizing-Systemizing (E-S) theory of typical sex differences suggests that individuals may be classified based on empathy and systemizing. An extension of the E-S theory, the Extreme Male Brain (EMB) theory suggests that autistic people on average have a shift towards a more masculinized brain along the E-S dimensions. Both theories have been investigated in small sample sizes, limiting their generalizability. Here we leverage two large datasets (discovery n = 671,606, including 36,648 autistic individuals primarily; and validation n = 14,354, including 226 autistic individuals) to investigate 10 predictions of the E-S and the EMB theories. In the discovery dataset, typical females on average showed higher scores on short forms of the Empathy Quotient (EQ) and Sensory Perception Quotient (SPQ), and typical males on average showed higher scores on short forms of the Autism Spectrum Quotient (AQ) and Systemizing Quotient (SQ). Typical sex differences in these measures were attenuated in autistic individuals. Analysis of "brain types" revealed that typical females on average were more likely to be Type E (EQ > SQ) or Extreme Type E and that typical males on average were more likely to be Type S (SQ > EQ) or Extreme Type S. In both datasets, autistic individuals, regardless of their reported sex, on average were "masculinized." Finally, we demonstrate that D-scores (difference between EQ and SQ) account for 19 times more of the variance in autistic traits (43%) than do other demographic variables including sex. Our results provide robust evidence in support of both the E-S and EMB theories.

Sex differences in social attention in autism spectrum disorder.

Although reduced social attention and increased nonsocial attention have been reported in individuals with autism spectrum disorder (ASD), the studies have relied on predominantly male samples and have been underpowered to examine sex differences. These processes may differ for females with ASD, who have been shown to be dissimilar to males in social motivation and nonsocial features, including circumscribed interests (CI). The goal of this study was to compare social and nonsocial visual attention between males and females with ASD on a validated eye-tracking paradigm. Eighty-five school-aged (6-10 years) males and females with and without ASD completed a paired preference task of face and object stimuli (half of which related to common CI). After covarying for chronological and mental age, the presence of concurrently presented CI images reduced prioritization and attention to faces for males more than females, replicating previous findings. ASD females maintained comparable attention patterns to typically developing females, suggesting that previous findings of reduced social attention and increased attention to CI-related objects in autism may be specific to males. These findings are also inconsistent with the "extreme male brain" theory of autism. The more normative orienting and attention to social stimuli for females with ASD may indicate distinct phenotypic characteristics relative to males and possibly serve as a protective effect. Autism Res 2018, 11: 1264-1275. © 2018 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: As autism is more commonly diagnosed in males, less is known about females with autism. Two areas of interest include the interests held by individuals with autism and how socially motivated they are. We used eye tracking as a way to understand these two areas. Our data reveal that elementary school-aged females (6-10 years) with autism attended to faces comparatively to females without autism, suggesting that (1) they were more socially motivated than males with autism and (2) the images of common interests were less motivating to them.

The Psychometric Properties of a Brief Version of the Systemizing Quotient

Abstract. The construct of systemizing – the drive to construct or understand systems – has an important role in the Extreme Male Brain theory of autism. While a brief version of the Systemizing Quotient (SQ) has been proposed, there is a need to assess its psychometric properties. This study assessed factorial and construct validity of an 8-item version of the SQ on a sample of 627 participants. A single-factor latent variable model with a single correlated error term showed adequate fit in a confirmatory factor analysis. This model also demonstrated metric invariance across genders when controlling for an effect of age on item responses. Reliability was acceptable, α = .72. As further evidence for construct validity, SQ scores showed expected relationships with mental rotation performance, trait anxiety, childhood extroversion, childhood agreeableness, and gender. Overall, the results indicated good psychometric properties for the brief version of the SQ, suggesting that this scale could be useful when researchers require a systemizing measure that is minimally burdensome to complete.

Commentary: Are we expecting too much from the extreme male brain theory of autism? A reflection on Kung etal. (2016).

Kung etal. (2016) contribute further evidence demonstrating no clear link between prenatal androgen exposure and the autism phenotype. Do these findings represent a nail in the coffin for the extreme male brain (EMB) theory of autism, or are we simply asking too much of the hypothesis? This commentary highlights the inconsistent findings that have appeared to undermine the EMB theory, but presents an argument that the data may not present an adequate test of the hypothesis. A research agenda is then outlined - the investigation of simple behavioural traits rather than the full combination of ASD behaviours - which may provide greater clarity as to how prenatal androgen exposure relates to developmental psychopathology.

Parent-Endorsed Sex Differences in Toddlers with and Without ASD: Utilizing the M-CHAT

Sex differences in typical development can provide context for understanding ASD. Baron-Cohen (Trends Cogn Sci 6(6):248–254, 2002) suggested ASD could be considered an extreme expression of normal male, compared to female, phenotypic profiles. In this paper, sex-specific M-CHAT scores from N = 53,728 18-month-old toddlers, including n = 185 (32 females) with ASD, were examined. Results suggest a nuanced view of the “extreme male brain theory of autism”. At an item level, almost every male versus female disadvantage in the broader population was consistent with M-CHAT vulnerabilities in ASD. However, controlling for total M-CHAT failures, this male disadvantage was more equivocal and many classically ASD-associated features were found more common in non-ASD. Within ASD, females showed relative strengths in joint attention, but impairments in imitation.

Sexuality and Gender Role in Autism Spectrum Disorder: A Case Control Study

The ‘extreme male brain theory of autism’ describes an extreme male pattern of cognitive traits defined as strong systemising abilities paired with empathising weaknesses in autism spectrum disorder. However, beyond these cognitive traits, clinical observations have suggested an ambiguous gender-typed pattern regarding several sexually dimorphic traits.The aim of the present study was to investigate if patterns of non-cognitive sexually dimorphic traits differed between the autism spectrum disorder and control groups. Fifty adults with autism spectrum disorder and intelligence within the normal range, and 53 neurotypical controls responded to questions on gender role, self-perceived gender typicality and gender identity, as well as sexuality. Measures used were a Swedish modification of the Bem Sex Role Inventory and questions on sexuality and gender designed for the purpose of this study. Our results showed that one common gender role emerged in the autism spectrum disorder group. Masculinity (e.g. assertiveness, leadership and competitiveness) was weaker in the autism spectrum disorder group than in the controls, across men and women. Self-perceived gender typicality did not differ between the groups but tomboyism and bisexuality were overrepresented amongst women with autism spectrum disorder. Lower libido was reported amongst both male and female participants with autism spectrum disorder compared with controls. We conclude that the extreme male patterns of cognitive functions in the autistic brain do not seem to extend to gender role and sexuality. A gender-atypical pattern for these types of characteristics is suggested in autism spectrum disorder.

The Sex Ratio of Full and Half Siblings of People Diagnosed with an Autism Spectrum Disorder: A Danish Nationwide Register Study

In the extreme male brain theory of autism sex steroid hormones are hypothesized to influence brain development and to mediate sex differences in developmental psychopathology. Within this scope we examined the sex ratio (proportion of males) in siblings of individuals diagnosed with autism spectrum disorders (ASD). We did a nationwide, register based cohort study of the sex ratio in 17,380 siblings of the 10,297 patients diagnosed with ASD at age 17years and younger and registered in the nationwide Danish Psychiatric Central Register between 1994 and 2012. Among the 17,380 siblings 8,828 were males and 8,552 females. This yields a sex ratio of 0.508, which is not different from the Danish live birth sex ratio of 0.513 during the relevant years (P=0.18). Overall, our findings provide no support for the hypothesis that there are relatively more males among the siblings of people with ASD. Accordingly, our results do not give support to the extreme male brain theory of autism.

Brief Report: The Relationship Between Visual Acuity, the Embedded Figures Test and Systemizing in Autism Spectrum Disorders

Enhanced performance upon the Embedded Figures Test (EFT) in individuals with autism spectrum disorder (ASD) has informed psychological theories of the non-social aspects that characterise ASD. The Extreme Male Brain theory of autism proposes that enhanced visual acuity underpins greater attention to detail (assessed by the EFT) which is a prerequisite for Systemizing. To date, however, no study has empirically examined these relationships. 13 males with ASD and 13 male controls were assessed upon tasks argued to reflect these levels of processing. The ASD group were found to have significantly greater visual acuity, EFT performance and Systemizing ability than the control group. However, regression analysis revealed that the strongest relationship was between visual acuity and EFT performance.

The Extreme Male Brain Theory of Autism and the Potential Adverse Effects for Boys and Girls with Autism

Autism, typically described as a spectrum neurodevelopmental disorder characterized by impairments in verbal ability and social reciprocity as well as obsessive or repetitious behaviours, is currently thought to markedly affect more males than females. Not surprisingly, this encourages a gendered understanding of the Autism Spectrum. Simon Baron-Cohen, a prominent authority in the field of autism research, characterizes the male brain type as biased toward systemizing. In contrast, the female brain type is understood to be biased toward empathizing. Since persons with autism are characterized as hyper-systemizers and hypo-empathizers, Baron-Cohen suggests that, whether they are male or female, most possess an "extreme male brain profile." We argue that Baron-Cohen is misled by an unpersuasive gendering of certain capacities or aptitudes in the human population. Moreover, we suggest that this may inadvertently favour boys in diagnosing children with Autism Spectrum Disorders. If this is correct, it could also have rather serious consequences for treatment and services for girls (and women) on the Autism Spectrum.

Sex differences in children with autism spectrum disorders compared with their unaffected siblings and typically developing children

This study examined the nature of cognitive and behavioral sex differences in children with autism spectrum disorders (ASDs) and two comparison groups: a group of typically developing (TD) children and a group of unaffected siblings of ASD children. Sex differences in core autistic symptoms, co-occurring behavioral symptoms, and cognitive styles were assessed in each group. Females with ASD were less severely affected than IQ- and age-matched males with ASD in the communication and repetitive stereotyped behavior domains, as measured by the ADI-R, but such sex differences were less significant than they were in the unaffected sibling group. Several behavioral/emotional symptom scores were significantly higher in male siblings than in female siblings. However, the ASD and TD groups did not show sex differences in any behavioral/emotional symptom scores. Males were superior in systemizing relative to empathizing, while the opposite was true for females in the unaffected sibling group and the TD children group; however, both males and females were superior in systemizing relative to empathizing in the ASD group. Our findings support the extreme male brain theory of autism, and further studies are needed to understand the mechanisms behind and developmental perspectives on the nature of sex differences in ASD.

Extreme Male Brain Theory of Autism

Autism spectrum conditions (ASCs) are a category of neurodevelopmental disorders with symptoms of communication and social impairment, and the exhibition of restrictive and repetitive behaviours. Their occurrence is greater in males than females and this sex difference has played an important part in hypothesizing their etiology. The Extreme Male Brain (EMB) theory is a cognitive model proposed by Simon Baron-Cohen to explain the aforementioned sex differences and potential cause of ASCs. It is based upon his Empathizing Systemizing theory, which classifies individuals into one of five cognitive profiles (Type S, Type E, Type B, Extreme Type S and Extreme Type E). These cognitive profiles determine an individual’s ability to systemize and empathize. Systemizing is the ability to understand and derive the rules of a system, and requires deductive and analytical skills. Empathizing relates to understanding human emotion and behaviour, thus requires social and communication skills. Males tend to systemize better than empathize while females have an opposite profile. Based upon the EMB theory, autistic individuals would possess an Extreme Type S profile as their impairments in social communication can be explained by a deficit in empathizing, while their preoccupation with patterns and detail-oriented behaviour can be related to their high systemizing. Together, these cognitive models have resulted in the Foetal Testosterone (fT) Theory, which implicates high prenatal testosterone as a risk factor for the associated hypermasculinized cognitive profile of individuals with ASCs. This review paper assesses the validity of the EMB and fT theories by reviewing the literature relating fT with autistic traits in the general population. The seven studies confirmed a correlation between higher fT levels and an increase in autistic traits, but limitations need to be considered when generalizing this information to an ASC sample.

The Relationship Between Systemising and Mental Rotation and the Implications for the Extreme Male Brain Theory of Autism

Within the Extreme Male Brain theory, Autism Spectrum Disorder is characterised as a deficit in empathising in conjunction with preserved or enhanced systemising. A male advantage in systemising is argued to underpin the traditional male advantage in mental rotation tasks. Mental rotation tasks can be separated into rotational and non-rotational components, and circulating testosterone has been found to consistently relate to the latter component. Systemising was found to correlate with mental rotation, specifically the non-rotational component(s) of the mental rotation task but not the rotational component of the task. Systemising also correlated with a proxy for circulating testosterone but not a proxy for prenatal testosterone. A sex difference was identified in systemising and the non-rotational aspect of the mental rotation task.

Are autistic traits autistic?

According to the extreme male brain theory of autism (Baron-Cohen, 2002), autistic traits would be extreme manifestations of typical male behaviours. The Auyeung et al. (2009) paper establishes a link between autistic traits and higher fetal testosterone (fT) levels in typically developing children. We argue that the construct behind this relationship needs further investigation. First, the link between fT levels and sexually dimorphic traits, that are for example, associated with empathizing and systemizing, is controversial. Likewise, describing autistic behaviours as being extreme male-like is debatable. The cerebral hemisphere laterality pattern of individuals with autism also seems to differ from the pattern typically observed in males. Moreover, the parallel that should exist, according to the fT theory, between individuals with autism and individuals with congenital adrenal hyperplasia (CAH), because of their high fT levels, is unclear. The theory implying fT levels in autism fails to account for a big part of autism, and the link between fT and normal 'autistic traits' hardly demonstrates the causal link between fT and autism.

Positive and negative gaze perception in autism spectrum conditions

Eyes are key social features providing a wealth of information about the attention, interest, emotion, and intention of others. Humans are typically very adept at detecting gaze direction, but there is a large decrement in gaze discrimination ability when eye images change from positive to negative polarity. This is thought to show an expert system for gaze perception that applies a contrast-specific heuristic to determine where someone else is looking. Autism spectrum conditions (ASC) are characterized by social deficits including difficulties in face-processing and in the social use of gaze. People with ASC are thought to have less expertise for gaze processing compared to typical controls, though little research has tested this. We investigated gaze direction perception in typical males and females, and males with ASC using facial stimuli with positive or negative polarity of the eyes. Results showed that the ASC group was worse at judging gaze direction with positive stimuli, and showed less of a decrement in performance when eye stimuli changed from positive to negative polarity. The differences in gaze perception for the ASC group were most evident when information from the eyes was more difficult and ambiguous. Typical females performed better at gaze direction detection with positive polarity than typical males, who in turn performed better than males with ASC. This latter finding is consistent with the extreme male brain theory of autism, and with the idea that people with ASC have less gaze expertise.

Comorbid childhood gender identity disorder in a boy with Asperger syndrome

IN AUTISTIC PSYCHOPATHY, Hans Asperger described that ‘the autistic personality is an extreme variant of male intelligence’.1 Consistent with this notion, Baron-Cohen proposed the ‘extreme male brain theory of autism’.2 By quoting this theory, gender dysphoria in female subjects with Asperger syndrome (AS) could be explained logically. But a literature search yielded no boys with AS and gender identity disorder (GID). Hereby we present such a case. Informed written consent was obtained from the patient's parents. A 5-year-old boy was referred to Child Psychiatry, Sapporo Ayuminosono because of his poor social skills. He had no peri-/neonatal complications. In his infancy he passed early motor and language landmarks without significant delay. Single words were developed at the age of 1 year and communicative phrases were observed at 2.2 years of age. Preoccupations with specific colors and figures were observed. He had limited interaction with others, difficulty in developing peer relationships and was underresponsive in social situations. He liked making his own rules and frequently lost his temper when these were broken. On the Wechsler Intelligence Scale for Children-III he had a full-scale IQ of 92 (verbal IQ 90, performance IQ 96) at the age of 7.6 years. Although his appearance was obviously that of a boy, he spoke in a girlish manner and covered his mouth with a hand when he laughed, as female individuals commonly do. He had very limited interaction with boys and his preferred playmates were girls. He was not interested in stereotypical boy's toys and had a marked preoccupation with feminine activities. He liked cute characters in TV animations and always painted cute girls surrounded with many lovely hearts and flowers. At home he tended to dress in girlish clothes and wear a ribbon in his hair. He regretted being a boy and often showed his desire to be a girl and asserted that he would grow up into a woman. These symptoms have been observed throughout the follow-up period of more than 2 years. Based on these symptoms, we diagnosed him as having AS and GID in accordance with the ICD-10 criteria. Most of the gender-related symptoms in autistic spectrum disorders (ASD) could be related to behavioral and psychological characteristics of autism. For example, a boy with ASD might have a sense of belonging to the female sex after being bullied by male peers. Transvestism in ASD may arise from a preoccupation with specific clothes such as a flared skirt which satisfies their tactile sensation. In their youth, ASD subjects can sometimes develop a unique confusion of identity that occasionally expands to gender-related problems. But these views do not explain the present case. For the diagnosis of GID in ASD, sufficient language abilities and sufficient follow-up time are essential. The present case fulfills these requirements. If the present patient continues to have gender-related symptoms into adulthood, we would need to treat him following an international standard.

How to Test the Extreme Male Brain Theory of Autism in Terms of Foetal Androgens?

We are writing to comment on Falter et al’s recent paper in JADD, ‘‘Visuo-spatial Processing in Autism: Testing the Predictions of Extreme Male Brain (EMB) Theory’’ which attempts to test 2 hypotheses. The authors present intriguing data regarding the degree of overlap between sexually dimorphic cognitive tasks and tasks that are altered in autism spectrum conditions (ASC). However, mental rotation is not an ideal task for testing the elevated foetal testosterone (fT) hypothesis of ASC. As the authors themselves note, mental rotation is not correlated with 2D:4D (Falter et al. 2006) and girls with elevated exposure to fT as a result of congenital adrenal hyperplasia (CAH) are not faster or more accurate at mental rotation (Hines et al. 2003, Malouf et al. 2006). Hines argues that sex differences in mental rotation may arise from sex differences in neonatal testosterone rather than prenatal levels. While it is possible that prenatal and neonatal levels are correlated, no-one has tested this experimentally. Secondly, whilst targeting appears to be a better index of fT exposure, in that females with CAH perform better on this relative to control females (Hines et al. 2003), the task used by Falter et al. is quite different from that used in the CAH study and did not show a sex difference in their 2006 study. It is also possible that problems with motor coordination (dyspraxia) in the ASC group (unrelated to fT exposure) affected their abilities on this task. Thirdly, the embedded figures task was significantly related to 2D:4D in a larger sample of adults (Falter et al. 2006), but this relationship was not seen in the current study (probably due to low power). There is only one published report using a similar task in girls with CAH, who were masculinized on this task (Resnick et al. 1986). It is difficult to find any cognitive measure which we can be certain is a proxy measure of fT exposure. If we are to use a cognitive task in this way, the focus should be on tasks where multiple different methodologies implicate fT, including studies of females with CAH, males with androgen insensitivity, correlations with digit ratio, and correlations with amniotic testosterone levels (BaronCohen et al. 2005). Converging evidence is also needed when physical proxies are used. Digit ratios, while a promising measure, must be interpreted with caution given recent studies suggesting the ratios may not be stable in children (McIntyre et al. 2006), large variation with ethnicity (Manning et al. 2004), and the possibility that individual differences in 2D:4D may also reflect genetic differences unrelated to fT (Paul et al. 2006). Rebecca Knickmeyer is supported by an NIMH training grant (T32 MH019111-13), a National Alliance for Autism Research (NAAR) Biomedical Grant, and the Foundation of Hope for Research and Treatment of Mental Illness. Simon Baron-Cohen, Bonnie Auyeung, and Emma Ashwin’s work is supported by the Nancy Lurie-Marks Family Foundation and the Medical Research Council (MRC) UK. In addition Bonnie Auyeung is supported by a scholarship from Trinity College, Cambridge. R. C. Knickmeyer (&) Department of Psychiatry, University of North Carolina-Chapel Hill, CB #7160, Chapel Hill, NC 7023, USA e-mail: rebecca_knickmeyer@med.unc.edu