Olga S. Alekseeva

Background. Fluid intelligence is an integral cognitive ability that involves solving new non-standard problems. It strongly predicts academic and professional achievement, whereas a low level of fluid intelligence is an important predictor of learning problems. Clinical studies of fluid intelligence are of interest for the development of training programs in various groups of children with special needs. This article presents a study on fluid intelligence in children with learning disabilities.

Objective. This study aimed to investigate characteristics of fluid intelligence and its relationships with other cognitive characteristics in children with learning disabilities.

Design. This study involved 93 children, divided into two groups: 55 typically developing children (control group) and 38 children with learning disabilities (clinical group). To assess intelligence characteristics, this study employed the Kaufman Assessment Battery for Children (KABC-II) and the Wechsler Intelligence Scale for Children Fifth Edition (WISC-V).

Results. A reduction was found in fluid intelligence, working memory, short-term memory, long-term memory, processing speed, visual-spatial abilities, and verbal abilities in the group of children with learning disabilities compared to the control group. In the clinical group, fluid intelligence was strongly associated with a greater number of cognitive parameters compared to the control group.

Conclusions. It is possible to assume that a close connection of fluid intelligence with the assessed cognitive characteristics in the group of children with learning disabilities may be due to general challenges in cognitive development.

Background. The assertion of sex differences in verbal abilities is a highly controversial subject. Some studies have demonstrated a female advantage; other studies have found higher rates in males. The results depended on the type of verbal ability that was studied, the cultural context, and the ages of the subjects. There are two types of theories that have been developed to explain the existence of sex differences in cognitive abilities. Social theories explain the differences as caused by social determinants. Biological theories consider biological factors such as prenatal development conditions and hormone levels, among others, as the cause of sex differences.

Objective. To investigate sex differences in verbal abilities in children of different ages.

Design. Two different editions of Wechsler tests were used. For children age 2.5 to 5 years, the Wechsler Preschool Primary Scale of Intelligence (WPPSI-IV) was used. For children age 6 and older, we administered the Wechsler Intelligence Scale for Children (WISC-V). The total sample included 313 children.

Results. The study found significant sex differences in performance on the Verbal Comprehension Scale in children of different ages. At the age of 2 to 4 years, the girls performed better than the boys. In the group of boys, there was a significant increase in verbal abilities at the age of 8–9 years. By the age of 10–11 years, boys began outperforming girls on the Verbal Comprehension Index. Scores on the Verbal Comprehension and Visual Spatial subtests for the boy sample showed stronger correlations than in the girl sample in all age groups.

Conclusion. Sex differences in verbal abilities varied depending on the age of the children. The boys showed a stronger integration of their verbal abilities into the structure of their intelligence than the girls.