Over 4,500 men were studied, all of whom had been born in Helsinki, Finland, between 1934 and 1944.
Their heights had been measured an average of eight times during the first year of life. The researchers linked these measurements to their educational levels and information on income and occupation, taken from the 1990 census.
The analysis showed that boys who were taller between birth and 1 year earned more than their shorter peers, irrespective of family background. Growth after the first 12 months seemed to be much less important.
The taller a boy was at the age of 1 year, the more money he was likely to be earning in 1990. Earnings increased by 3.5% with every additional 2 cm of height.
And a child who had been 72 cm or less in height at the age of 1 was twice as likely to be doing manual work in adulthood as a boy who had been over 80 cm in height at that age.
Those who grew slowly as infants tended to achieve lower levels of education than those who grew more quickly, prompting the authors to wonder if slow physical growth might also be accompanied by slow brain development or reduced physical activity and therefore less sensory stimulation.
Journal
Archives of Disease in Childhood