People's personalities are being determined well before birth, but the culprit is not the stars. It's the sun.

In a study made at Aarhus University Hospital, Denmark, people who were born in the winter months are said to be more at risk of having schizophrenia. A study of people who committed suicide in England and Wales meanwhile also found out that 17 percent more people who had committed suicide had birthdays in April, May and June than in the rest of the year.

The recent explanations for this have concentrated on the more direct effects of the seasons on the mother: how much sunshine a pregnant woman is exposed to, or the effects of temperature. Researchers from London also collated their findings on the relationship between the seasons and the development of babies. When they went to Singapore, however, where the temperature remains at a constant 80 degrees all year round, they found no season-of-birth effect at all.

Scientists are still studying the effects of lack of sunshine to neurodevelopmental abnormalities. They are hoping to someday understand the biological basis for this seasonal blip in the incidence of mental disorder, in order to fix it.