Assessment of the etiology of alexithymia is in most studies hindered by recall bias. The aim of the present study was to assess the significance of individual developmental factors at the age of five years for alexithymia in late adolescence. By using data from a child welfare centre check-up at the age of five years, it was possible to avoid recall bias.

The sample consisted of 723 subjects, who were comprehensively examined at the age of five years at a child welfare centre where their state of health, verbal, gross motor, visuo-motor, socio-emotional, and cognitive development were assessed. In late adolescence (mean age 19 years) their alexithymic features were measured using the 20-Item Toronto Alexithymia Scale (TAS-20).

In females, none of the developmental factors remained associated with later alexithymic features in the multivariate analyses. However, in males, emphasis on the variables measuring speech development was important. In particular, a variable measuring the ability to comply with multi-part instructions was strongly related with alexithymic features in late adolescence.

The results suggest speech development is a significant factor in the developmental process of alexithymia, at least in males. It is possible that children who have impaired language skills and therefore struggle in social situations have a higher risk of developing alexithymia. This emphasizes the need for further research, to assess how the inadequate speech development predisposes to the emergence of alexithymic features and whether it is a gender-specific phenomenon.