SES is calculated according to Largo et al. (1990, Dev. Med. Child Neur., 32:30-45) by means of a six-point score of both maternal education and paternal occupation. The lowest possible SES score for either the mother or the father is 1, the highest 6. The overall SES score is a simple addition of the 2 individual scores resulting in a value between 2 and 12.
In 2018, coding was standardized to synchronize areas of profession with years of education. Please consult the SES Scoring Table.