This research study explores the differences in executive functioning (EF) between normally developing children and children with Sex Chromosome Trisomies (SCT) between 1 and 8 year old. Rather...Show moreThis research study explores the differences in executive functioning (EF) between normally developing children and children with Sex Chromosome Trisomies (SCT) between 1 and 8 year old. Rather than the typical karyotype XX or XY, people with SCT have three sex chromosomes, resulting in karyotype XXY, XYY or XXX. Executive functions can be defined as mental processes that allow people to control their actions. The BRIEF, BRIEF-P and MEFS were utilized to obtain information about the development of EF. A total of 147 participants between the ages of 2,8 and 7,6 years old took part in the study. 74 participants with SCT (Mage= 4,8, SD = 1,3) and 70 (Mage= 4,5, SD = 1,0) participants without SCT. Analysis methods used were independent samples t-tests, correlations and Fisher-Z transformations. It was found that there are differences in executive functioning as a whole between children with and without SCT. The differences in working memory, inhibition and cognitive flexibility are small. Bigger differences between children with and without SCT were found with regards to their emotional control and cognitive flexibility. The research concludes that developmental delay regarding executive functioning is visible in children with SCT before the age of 8 years old. When children mature these differences become more obvious as the gap between what is expected with regards to EF increases faster than children with SCT improve their EF skills. Additional research is needed in order to discover whether the EF profile found is unique for children with SCT and what implications this has. Future studies should also investigate the ways EF impacts children with SCT and which treatments yields the most benefits for them. Support with regards to the development of EF in children with SCT is crucial in order to enable them to maximize the possibilities in their lives.Show less