Is the EQ genetically determined

Development deficit / development retardation

Introduction / definition

A development deficit or development retardation refers to a delay in the physical, mental or emotional development of children compared to the development stage of healthy, normally developed children of the same age. A deviation from the norm by one to two standard deviations (IQ between 70 and 85 or EQ between 0.7 and 0.85) is considered to be the limit range; a deviation of two standard deviations (IQ <70 or EQ <0.70) clearly indicates a delay in development. In addition to a purely quantitative skill-related definition, the question of age-appropriate participation is also important.

Development delays can be global or circumscribed and affect the following areas:

  • motor development (gross and fine motor skills)
  • cognitive development
  • Language development (language comprehension and active language)
  • emotional and social development
  • School skills such as writing, reading and arithmetic
As defined by the cut-off (EQ / IQ 70), a statistical prevalence of at least 2.5% is to be expected; a frequency of 5-15% has been described for some circumscribed disorders.

Possible causes are damage to the brain during pregnancy, childbirth (e.g. in the case of extremely premature birth, asphyxia, other perinatal problems) or in early childhood, congenital or acquired diseases of the nervous system, neurometabolic diseases or traumatic brain injuries. Traumatic experiences, attachment disorders or deprivation can also result in development delays.

Mental retardation is at least 50% genetic, and degenerative CNS diseases are more than 90%. However, the etiology remains unclear in about half of the cases. Boys are more often affected than girls, which shows a gender-specific expression with a hereditary connection.


Numerous scores and test instruments are available, which can be used to determine the child's level of development for the various areas and to compare it with the average age. If no standardized tests are available (due to age, sociocultural background or other reasons), the diagnosis must be based more on the clinical assessment of an experienced specialist in child development (developmental pediatric trained pediatricians or psychologists, possibly also occupational and learning therapists) based. A diagnosis of developmental delay includes all areas of motor skills, perception, cognitive properties and language development.

The indication for additional examinations (e.g. MRI, EEG, human genetic / cytogenetic and metabolic clarification) should be reserved for paediatricians (ideally developmental pediatricians and pediatric neurologists).

Therapy recommendations

Therapy options are specific causal as well as secondary preventive. In addition to the specific treatment of any underlying disease, in view of the high rate of secondary problems and comorbidities that can be associated with developmental delays, it is important to identify affected children at an early stage and to determine their individual support needs. A number of children continue to develop at their own slow pace due to a fundamental developmental disorder and will not be able to catch up. For them, however, early intervention is indicated in order to establish a "FIT" between them and their environment and to accompany them on their way to a suitable place in society (link for further reading). Other children, on the other hand, benefit greatly from early therapy offers with which they can fully or partially compensate for their deficit. In addition to physiotherapy or early childhood education, examples are early speech therapy for children with speech development disorders, occupational therapy for children with motor deficits (UEMF) or specific therapies for children with severe hearing or visual disorders. In addition to health insurers, the IV and (in the case of special educational measures such as early childhood education, speech therapy, audio education and low-vision therapy) the school communities and the canton are responsible for paying for these measures.


Defined developmental disorder of motor functions (UEMF): Link AWMF online / Defined developmental disorder of motor functions (UEMF).

Intellectual disability: AWMF online, intellectual disability.

Language development disorders (SES), diagnosis of, taking into account circumscribed language development disorders (USES): [[Language development disorders (SES), diagnosis of, taking into account circumscribed language development disorders (USES) | AWMF online, language development disorders (SES), diagnosis of, taking into account circumscribed language development disorders ( USES)]].

Mental disorders in infants, toddlers, and preschoolers: AWMF online, Mental disorders in infants, toddlers, and preschoolers.


American Academy of Neurology. (2014). Testing For The Cause of Global Developmental Delay. Retrieved from AAN Guideline Summary for Parents and Caregivers.

Moeschler, J., & Shevell, M. (2014, August). Comprehensive Evaluation of the Child With Intellectual Disability or Global Developmental Delay. Pediatrics, e903-e918.

Perna, R., & Loughan, A. (2013). Early Developmental Delays: A Cross Validation Study. J Psychol Abnorm Child, 1 (2).

February 2019
PD Dr. M. of Rhine