Sander Begeer

Vrije Universiteit Amsterdam | VU · Department of Developmental Psychology

The current study examined the association between interpersonal social goals (i.e., agentic and communal goals) and bullying behaviour for autistic adolescents (n = 108, Mage = 15.25 years, SD = 1.65) and neurotypical adolescents (n = 592, Mage = 13 years, SD = 0.5). Bullying behaviour was assessed using both self- and peer-reported measures. Agen...

Prior research has established differences between autistic and non-autistic individuals across the domains of executive function (EF). While some early theories portrayed these differences as universal to the autism spectrum, recent findings have been quite mixed. Factors like small samples, the components of EF being measured, age and intelligenc...

Background: Belief in conspiracy theories has emerged across times and cultures. While previous accounts attributed conspiracy beliefs to mental health conditions, accumulating research suggests that conspiracy theories are common among the general population. In the present study we examined whether conspiracy mentality - that is, a general predi...

Autism, a diverse neurodevelopmental disorder, sees a multitude of treatments, including controversial vaccine-related ones. Despite evidence against their effectiveness and potential harm, these treatments persist globally. We analysed the use of alternative treatments in two studies: a survey (N=1989) and a clinical care study (N=4520), both reve...

Despite an estimated population of 10 million autistic individuals, there is still a significant lack of research on autistic adults in China. This study aimed to investigate the extent and factors influencing community integration (employment, independent living and friendship) and life satisfaction among young autistic adults in China, and compar...

Inclusive education policies stimulate children with special educational needs, including autism, to attend regular education. We aimed to explore change over time in school placement and transitions of autistic children since the introduction of an inclusive education policy in the Netherlands (2014) and to examine the role of individual child cha...

It is crucial to arrive at a comprehensive understanding of the types of daily activities autistic adults typically engage in. However, previous research has almost exclusively focused on vocational or education activities. Further, it remains unclear how and whether specific daily activities participation rates change proportionally over time, var...

Background Many autistic people, particularly women, do not receive an autism diagnosis until adulthood, delaying their access to timely support and clinical care. One possible explanation is that autistic traits may initially be misinterpreted as symptoms of other psychiatric conditions, leading some individuals to experience misdiagnosis of other...

Differences between autistic and non-autistic individuals in perception of the temporal relationships between sights and sounds are theorized to underlie difficulties in integrating relevant sensory information. These, in turn, are thought to contribute to problems with speech perception and higher level social behaviour. However, the literature es...

Previous research on employment outcomes of autistic adults mainly assessed if they work and under what terms, with mostly anecdotal descriptions of where they work. This study aimed to identify the employment sector distribution of autistic employees compared to the general workforce in the Netherlands and to explore possible background predictors...

Temporal alignment is often viewed as the most essential cue the brain can use to integrate information from across sensory modalities. However, the importance of conscious perception of synchrony to multisensory integration is a controversial topic. Conversely, the influence of cross-modal incongruence of higher level stimulus features such as pho...

Developing a positive view of the self is important for maintaining a good mental health, as feeling negative about the self increases the risk of developing internalizing symptoms such as feelings of depression and anxiety. Even though autistic individuals regularly struggle with these internalizing feelings, and both self-concept and internalizin...

In the past 40 years, accumulating evidence suggested that autistic individuals are at an increased risk of suicidal thoughts and behaviors. This study examined the occurrence of various potential risk factors for lifetime suicidal behavior and suicidal thoughts in the past month in a Dutch cohort (Netherlands Autism Register) of autistic individua...

Autistic adults experience high rates of unemployment, yet research investigating what predicts employment success produces inconsistent results. By utilising longitudinal person-oriented analyses, this study aimed to identify employment trajectories of autistic adults to better understand what may predict stable autistic employment. Participants w...

Psychosocial characteristics of children with autism were collected before the COVID-19 pandemic and compared with data collected during the pandemic. The results show a surprising improvement, especially from T0 to T1. Girls and children attending special education showed increased difficulties over time, while older children showed fewer difficul...

Differences between autistic and non-autistic individuals in perception of the temporal relationships between sights and sounds are theorized to underlie difficulties in integrating relevant sensory information. These, in turn, are thought to contribute to problems with speech perception and higher level social behaviors. However, the literature es...

Studies on the impact of the COVID-19 pandemic on autistic children’s psychosocial outcomes have shown mixed results. In the current study we aimed to gain a better insight into the effect of the COVID-19 pandemic by comparing psychosocial outcomes collected pre-pandemic with data collected during the pandemic. We used the Strengths and Difficultie...

The current study evaluated a brief, informant-based autism interview: the Developmental, Dimensional and Diagnostic Interview – Adult Version (3Di-Adult). Feasibility, reliability and validity of the Dutch 3Di-Adult was tested amongst autistic participants (n = 62) and a non-autistic comparison group (n = 30) in the Netherlands. The 3Di-Adult cons...

Temporal alignment is often viewed as the most essential cue the brain can use to integrate information from across sensory modalities. However, the importance of conscious perception of synchrony to multisensory integration is a controversial topic. Conversely, the influence of cross-modal incongruence of higher level stimulus features such as pho...

Individuals with autism increasingly enroll in universities, but little is known about predictors for their success. This study developed predictive models for the academic success of autistic bachelor students ( N = 101) in comparison to students with other health conditions ( N = 2465) and students with no health conditions ( N = 25,077). We appl...

This study provides insight into sixty years of autism diagnostics in the Netherlands. The historical changes in the period of 1960-2020 were investigated on the basis of seven factors, including the age of diagnosis, intelligence and type of diagnostician. The data are derived from participants (n = 2643) of the Dutch Autism Register (NAR: Nederla...

There is broad interest in discovering quantifiable physiological biomarkers for psychiatric disorders to aid diagnostic assessment. However, finding biomarkers for autism spectrum disorder (ASD) has proven particularly difficult, partly due to high heterogeneity. Here, we recorded five minutes eyes-closed rest electroencephalography (EEG) from 186...

Autism is a heterogeneous neurodevelopmental disorder for which a large variety of treatments are offered, including alternative treatments. Vaccine-related treatments (treatments falsely claiming to cure autism by addressing its alleged cause: routine childhood vaccines such as MMR) continue to be offered worldwide, despite widespread evidence aga...

Lay abstract: It has been known for a long time that individuals diagnosed with autism spectrum disorder perceive the world differently. In this study, we investigated how people with or without autism perceive visual and auditory information. We know that an auditory and a visual stimulus do not have to be perfectly synchronous for us to perceive...

Oratie Sander Begeer Gehouden op 20-5-2022 aan de Vrije Universiteit Amsterdam Geachte aanwezigen, Nadat de titel van deze oratie bekend werd, kreeg ik al snel vragen van mensen met een autismediagnose. ‘Wiens spiegel?’ ‘En waarom achter de spiegel en niet ervoor?’ Aan het eind van deze oratie zal ik antwoord geven op deze vragen. Deze interactie k...

Lay abstract: There are different words to describe people with an autism diagnosis. For instance, we can put the person before autism (e.g. 'person with autism'), or we can put autism before the person (e.g. 'autistic person'). Previous research showed that autistic adults in English-speaking countries generally liked it better when autism is pla...

Previous studies have suggested that autistic adults may be negatively affected by the COVID‐19 pandemic and its associated restrictions. In this study, we examined continuity and change in loneliness and stress, and their predictors, in 448 autistic and 70 non‐autistic adults living in the Netherlands. Autistic participants were assessed on three...

Anger regulation is a challenge for children with autism spectrum disorders (ASD). We investigated if attention‐based cognitive behavioral treatment, based on mindfulness cognitive therapy (MBCT) and dialectical behavior therapy (DBT), reduces aggressive behavior and improves anger coping in school‐aged autistic children ( n = 51). Children were ra...

Lay abstract: Autism is a condition that is characterised by social communication difficulties and restrictive and repetitive behaviours or interests. Autism can present in many different ways and various interventions are available. Some interventions are conventional, and they are recommended to be used for children with autism (guideline therap...

Lay abstract: More and more members of the autistic community and the research field are moving away from the idea that there will be a single biological or cognitive explanation for autistic characteristics. However, little is known about the complex dynamic processes that could explain why early difficulties in the language and motor domain ofte...

Background: Having twin and non-twin siblings might influence autistic traits both prenatally and postnatally. The twin testosterone transfer hypothesis suggests that girls with a twin brother are exposed to higher levels of prenatal testosterone than girls with a twin sister, and that increased testosterone exposure masculinizes neural developmen...

Impaired social-emotional reciprocity is a defining feature of Autism Spectrum Disorder (ASD). Deficits in reciprocity can be difficult to assess, particularly in adults with average or above average intelligence. The recently developed Interactive Drawing Test (IDT) measures reciprocity in children and adolescents with and without ASD based on spo...

Individuals with autism increasingly enroll in universities, but researchers know little about how their study progresses over time towards degree completion. This exploratory population study uses structural equation modeling to examine patterns in study progression and degree completion of bachelor’s students with autism spectrum disorder ( n = 1...

Among 1212 adult participants with and without autism, binary logistic regression analyses were used to investigate whether having an autism diagnosis and the extent to which autistic traits are present were predictive of having an autistic partner. Autistic participants (12.3%) more oft en had autistic partners than participants without autism (7%...

Background Autistic adults, particularly women, are more likely to experience chronic ill health than the general population. Central sensitivity syndromes (CSS) are a group of related conditions that are thought to include an underlying sensitisation of the central nervous system; heightened sensory sensitivity is a common feature. Anecdotal evide...

Pre- and post-term children show increased autism risk. Little is known about gestational age (GA) prevalence among autistic children, and their respective autism phenotype. We compared prevalence of pre-, full- and post-term birth between a population-derived sample of N = 606 (137 females, 22.61%) autistic children and adolescents (mean age = 14....

Background Autism spectrum disorder and intellectual disability (ID) are linked to atypical sensory processing, but consensus lacks on the impact of their co-occurrence. We studied the impact of the presence of ID in autistic individuals on (1) sensory processing and (2) the relation between sensory processing and behavioral outcomes. Methods A sy...

Background: Having twin and non-twin siblings might influence autistic traits both prenatally and postnatally. The twin testosterone transfer hypothesis suggests that girls with a twin brother are exposed to higher levels of prenatal testosterone than girls with a twin sister. Prenatally, increased testosterone exposure could masculinize neural dev...

Although good quality housing and a socially cohesive neighborhood are associated with a higher well-being in the general population, housing is a rarely studied topic in autism research. In the present study, we describe the housing situation of a large sample of adults with autism and mostly (above) average intellectual abilities (n = 1429; 17 to...

Autism spectrum disorders are diagnosed globally, but recognition, interpretation and reporting may vary across cultures. To compare autism across cultures it is important to investigate whether the tools used are conceptually equivalent across cultures. This study evaluated the factor structure of the parent-reported Autism Spectrum Quotient Short...

Lay abstract: Previous research has shown that relatively few adults with autism have a paid job or live on their own. However, outcomes also vary a lot and may depend on many different factors. In this study, we examined the level of functioning and happiness of 917 adults with autism (425 men and 492 women) aged 18-65 years. Most of them were of...

Lay abstract: Autistic adults without a suspected intellectual disability reported several motor features such as having tremors, and stiffness in one's legs which are considered to be part of a complex of motor features called parkinsonism. This so-called parkinsonism was remarkably prevalent in middle-aged and older autistic adults in two indepe...

Background Autistic adults, particularly women, are more likely to experience chronic ill health than the general population. Central sensitivity syndromes (CSS) are a group of related conditions that are thought to include an underlying sensitisation of the central nervous system; heightened sensory sensitivity is a common feature. Anecdotal evide...

This RCT investigated whether participants’ sibling configuration moderated the effect of a Theory of Mind (ToM) intervention for children with autism. Children with autism aged 8–13 years (n = 141) were randomized over a waitlist control or treatment condition. Both having more siblings, as well as having an older sibling were related to better ou...

Background Despite a high prevalence of psychiatric conditions in autistic adults, research examining the diagnostic stability of psychiatric conditions diagnosed prior to autism is limited. Method The present study examined the occurrence of (1) psychiatric diagnoses obtained before autism was diagnosed, (2) psychiatric conditions co-occurring wi...

Background The social domain of autism has been studied in depth, but the relationship between the non-social traits of autism has received less attention. The Diagnostic and Statistical Manual of Mental Disorders (DSM-5) outlines four criteria that make up the non-social domain including repetitive motor movements, insistence on sameness, restrict...

Lay abstract: Everyone knows the feeling of letting one's mind wander freely in a quiet moment. The thoughts and feelings experienced in those moments have been shown to influence our well-being-and vice versa. In this study, we looked at which thoughts and feelings are being experienced by adults with autism spectrum disorder and compared them to...

The network approach to psychological phenomena advances our understanding of the interrelations between autism and well-being. We use the Perceived Causal Relations methodology in order to (i) identify perceived causal pathways in the well-being system, (ii) validate networks based on self-report data, and (iii) quantify and integrate clinical exp...

Prior research suggests that autistic adults are at increased risk for developing the core motor components of Parkinson’s disease (i.e., parkinsonism) though knowledge is limited to date. Therefore, we explore: (a) the prevalence of self-reported motor features typical of parkinsonism in two samples of older adults with an autism spectrum disorder...

Background Atypical sensory processing often impairs the emotional and behavioural functioning and social participation of autistic individuals. However, evidence lacks on the effect of cognitive abilities. Therefore, the aim of this study was to examine the moderating effect of cognitive abilities on both associations. Method We studied 241 indiv...

Lay abstract: Individuals on the autism spectrum often experience heightened or reduced sensory sensitivities. This feature was recently added to the diagnostic manual for autism (Diagnostic and Statistical Manual of Mental Disorders, 5th ed. (DSM-5)). To measure sensory sensitivities, the Sensory Perception Quotient (SPQ) has been developed. In t...

Autism spectrum disorder and anxiety are highly comorbid conditions. Understanding the underlying traits of anxiety in autism spectrum disorder is crucial to prevent and treat it efficiently. Hence, this study determined whether social communication difficulties or restricted repetitive behaviors are stronger risk factors for anxiety symptoms in au...

Background Autism is a behaviorally defined neurodevelopmental condition that is often associated with early developmental delays in language and motor domains. However, little is known about the complex dynamic processes that drive the co-development of such difficulties in children at-risk for atypical developmental trajectories. Using a longitud...

Background: Autistic individuals' enrollment in universities is increasing, but we know little about their study progress over time. Many of them have poor degree completion in comparison to students with other disabilities. However, longitudinal studies on study progression over time of autistic students (AS) in comparison to their peers are absen...

IntroductionImpaired reciprocity is a defining feature of autism spectrum disorder (ASD, DSM‑5; APA 2013). This study introduces a new test for reciprocal behaviour in children and adolescents with ASD, namely the interactive drawing test (IDT, Backer van Ommeren et al. 2017a).Method The quality of reciprocal behaviour was assessed in 392 youngster...

The number of students with Autism Spectrum Disorder (ASD) entering Universities is growing. Recent studies show an increased understanding of students with ASD in higher education. Yet, current research generally relies on small samples, lacks information about student characteristics prior to enrollment, and does not compare students with ASD to...

Er bestaan verschillende interventies om het inlevingsvermogen, ook wel theory of mind (ToM) vaardigheden genoemd bij kinderen met autismespectrumstoornis (ASS) te verbeteren. In het hier besproken onderzoek zijn kinderen met ASS (7–12 jaar oud; n = 140) willekeurig toegewezen aan een wachtlijstcontrole of een ToM-training. In de ToM-training werde...

Children with autism spectrum disorder (ASD) show atypical social behavior but vary in their social interaction style (SIS), ranging from social aloofness to awkward social approaches. In a 4‐year follow‐up study, we examined longitudinal stability and change of SIS in children and adolescents with ASD and a normal intellectual ability ( n = 55; me...

The network approach to psychological phenomena enables innovations for investigating the interrelation between autism spectrum disorder (ASD) and well-being. We combine the Perceived Causal Relations (PCR) methodology and network analysis in order to (i) identify causal pathways in the ASD well-being system, (ii) validate the networks found in emp...

Insomnia is a common source of distress in adults with autism spectrum disorder (ASD). Two characteristics of ASD could be relevant to insomnia complaints by hampering the entrainment of a circadian sleep-wake rhythm. First, sensory hyper-reactivity could lead to bright light avoidance and thus affect photoperiodic input to the circadian system. Se...

Many individuals with autism report generally low quality of life (QoL). Identifying predictors for pathways underlying this outcome is an urgent priority. We aim to examine multivariate patterns that predict later subjective and objective QoL in autistic individuals. Autistic characteristics, comorbid complaints, aspects of daily functioning, and...

Samen met onderzoekers van de VU ontwikkelde klinisch psychologe en behandelaar Tineke Backer van Ommeren de interactieve tekentest (IDT).¹ Een artikel over de meerwaarde van deze nieuwe, veelbelovende autismetest.

Background In recent years, an increasing number of studies have highlighted progress in ASD clinical practice and scientific research in China (Zheng & Zheng, 2015). However, little is known about the differences between clinical or scientific approaches to ASD between China and other countries. In our study we explored the impact of gender, comor...

Phenotypic elements of autism spectrum disorder can be masked by attention-deficit/hyperactivity disorder symptoms, potentially leading to a misdiagnosis or delaying an autism spectrum disorder diagnosis. This study explored differences in the age of autism spectrum disorder diagnosis between participants with previously diagnosed attention-deficit...

Youth with ASD often show limited or atypical empathic responsiveness. The direct effects of social skills interventions on enhancing empathic responsiveness is unknown. Data from a randomized controlled trial were used to investigate whether a Theory of Mind training improves the empathic responsiveness, measured through structured observations. T...

Children and adolescents with Autism Spectrum Disorder (ASD) often show comorbid emotional and behavior problems. The aim of this longitudinal study is to examine the relation between emotion control (i.e., negative emotionality, emotion awareness, and worry/rumination) and the development of internalizing and externalizing problems. Boys with and...