The association between General Mental Ability (GMA) and whole brain size was almost accepted universally. Association between the Performance Intelligence Quotient (PIQ) score with anatomical characteristics such as gender, height, weight, and brain size are also focused on many research articles. However, very little study has been made to…

At the level of the 50 U.S. states, an interconnected nexus of well-being variables exists. These variables strongly correlate with estimates of state IQ in interesting ways. However, the state IQ estimates are now more than 16 years old, and the state well-being estimates are over 12 years old. Updated state IQ and well-being estimates are…

Introduction: Findings regarding the relationship between IQ and comorbidity in autism and ADHD are inconsistent. Methods: Mothers rated 1,436 children with autism and 1,056 with ADHD without autism (IQs 9-149, ages 2-17) on the Pediatric Behavior Scale. Results: Children with IQs < 70 (vs. [greater than or equal to] 70) had less oppositional…

This follow-up study aimed to examine (a) the impact of 4.5 years participation in postsecondary education (PSE) on students with intellectual disability (ID) compared to adults with ID who did not participate in PSE, (b) whether a different impact on crystallized and fluid intelligence after 4.5 years would be found among PSE students with higher…

Relationships between sluggish cognitive tempo (SCT) and age and IQ were investigated in children with autism and/or ADHD covering broader age and IQ ranges than in previous studies. Mothers rated 1436 children with autism and 1,056 with ADHD (2-17 years, IQs 9-149) on Pediatric Behavior Scale SCT items. Increasing age correlated with SCT in the…

In this study, we investigated the direct and indirect associations of different cognitive-linguistic skills and Chinese reading comprehension in Hong Kong kindergarteners. We assessed 179 children's nonverbal IQ, cognitive-linguistic skills, word reading, listening comprehension, and reading comprehension. Results showed significant correlations…

Although extensive research has focused on the perceptual abilities of second language (L2) learners, a significant gap persists in understanding how cognitive functions like phonological short-term memory (PSTM) and nonverbal intelligence (IQ) impact L2 speech perception. This study sets out to investigate the discrimination of L2 English…

Early life stress (ELS) is associated with lower IQ and academic achievement; however, it remains unclear whether it additionally explains their discrepancy. In 2,401 children (54% girls, 30.2% migration background) from the population-based study Generation R Study, latent factors of prenatal and postnatal (age 0-10) ELS were estimated, and…

This study explores sex-differences in (a) rates and profiles of autism symptoms as well as in (b) the contribution of intellectual quotient (IQ) to autism symptom presentation in Down syndrome (DS). Participants were 40 males and 38 females with DS, aged 6 to 23 years. Autism symptoms were rated through the Autism Diagnostic Observation…

Executive functions (EFs) and intelligence (IQ) are phenotypically correlated. In twin studies, latent variables for EFs and IQ display moderate to high heritability estimates; however, they show variable genetic correlations in twin studies spanning childhood to middle age. We analyzed data from over 11,000 children (9- to 10-year-olds, including…

The Flynn effect, which advocated that there was a rise in the global IQ score, was widely accepted by the relevant scientific community. However, there are recent research findings that this effect has been reversed. In this study, both Flynn and anti-Flynn effects were investigated. The purpose of this study is to analyze students' general,…

Intelligence quotient (IQ), has been found to relate to the presence of internalising symptoms in autism spectrum disorder (ASD). This meta-analysis sought to clarify the direction of the relationship between IQ and two prevalent internalising symptoms, anxiety and depression, in adolescents with ASD. Secondly, this study aimed to highlight…

Tests of measurement invariance are essential to determining whether individual scores or group averages are comparable across populations. While international comparisons of mean IQ scores are common, tests of measurement invariance for intelligence test batteries (necessary for comparisons to be empirically supported) are rare. In this study,…

Adaptive functioning, or the suite of skills essential for real-world, day-to-day functioning, includes daily living, communication, and socialization abilities. Even in the absence of co-occurring intellectual disability (IQ < 70), difficulties in adaptive functioning are prominent in autism spectrum disorder (ASD). Further, ASD individuals…

Interpersonal Skills (ISs) and Executive Functions (EFs) are two groups of skills which are extremely relevant for children's cognitive, social and psychological development. As well as being interrelated, both can be modulated by other variables such as intelligence or sex. Many studies have tried to establish the relationship between them, but…