Height depends on month of birth

The authors used a population of 507,125 males subjects born over 10 years. Body height was evaluated at age 18 on birth month. The main result is that the average height of those born during spring is 0.6cm higher than the average height of those born in Autumn. Not only is there a difference between the 'January to June' and 'June to December' cohorts, but also a sinusoidal fluctuation over the year. This fluctuation was compared with the monthly variation in sunshine duration in Austria during the same interval. The authors suggest that the underlying physiological mechanism might involve the light dependent activity of the pineal gland.