Researchers Professor Janka Goldan from the Institute for Educational Research and Dr Franz G. Westermaier from the Wuppertal Institute for Research in Economics of Education (WIB) at the University of Wuppertal analysed data from more than 67,000 pupils in the fourth and ninth grades from the nationwide IQB education trends. The study analysed the influence of relative age, i.e. whether a child is older or younger within their grade level.

Relatively younger children are significantly more likely to be diagnosed

The result: children who are among the youngest in their year group are significantly more likely to be categorised as needing special educational needs. This is particularly evident in the areas of learning, language and emotional and social development. For pupils in the fourth grade, the probability of a corresponding classification was around 21 per cent higher, in the ninth grade even up to 27 per cent.

There were also significant differences in ADHD - attention deficit hyperactivity disorder. Fourth-graders, who are among the youngest in their class, are diagnosed with ADHD around 52 per cent more frequently than older children in the same year group.

Relative age differences influence diagnostic decisions

"Our results show that not only actual learning and behavioural characteristics play a role in diagnostic decisions, but also the relative age of a child within the grade level," explains Janka Goldan. "Younger children, especially in primary school, can be perceived as inattentive, impulsive or weaker learners compared to older classmates, although such differences are often developmental and age-related."

For their study, the researchers used a statistical method that takes advantage of the different school enrolment dates between the federal states, resulting in a quasi-experimental design. This enabled them to determine the causal influence of relative age on diagnostic decisions.

Diagnoses can shape educational pathways in the long term

A special educational needs status or an ADHD diagnosis can contribute to children receiving targeted support. At the same time, such decisions can have long-term negative consequences for educational biographies, for example through changed expectations, stigmatisation or school career decisions.

"What is initially a normal developmental difference between younger and older children can have long-term effects on the further course of education as a result of diagnostic decisions," says Franz G. Westermaier.

Researchers call for more development-orientated diagnostic procedures

The researchers are therefore in favour of more development-oriented and standardised diagnostic procedures. Decisions about the need for special educational support or ADHD should not be based on subjective assessments, but should explicitly take into account a child's age in relation to their peers. In addition, they recommend independent multi-professional diagnostics and support concepts that are orientated towards the individual needs and development of the children.

The study "Does the Early Bird Catch the Label? Relative Age Effects in the Assessment of Special Educational Needs and ADHD: Evidence from Germany" was published in the journal Exceptional Children.