What does your birthday say about you? Possibly more than you think.
The Royal Institution's Kate Mulcahy has made a video summarising current research about the seasonal birth effect: where certain characteristics are linked to birth dates.
Studies show babies born in summer are more likely to be smokers, or short sighted and are less likely to develop schizophrenia or be left-handed than winter babies.
As Mulcahy notes, one theory to explain this is those born in winter will be conceived in May and June and thus exposed to more sunlight in early pregnancy, which can affect how the brain develops.
As for how accurate the seasonal birth effect is? For now, we can only prove a link rather than causality. Which means "we need to take it with a pinch of salt">
We can't say, for example, why these things are actually happening at all. We can't say being born in winter definitely contributes towards suffering from schizophrenia. All we know is there's a link in the data sets that have been analysed.
Earlier this month, we covered research from Columbia University linking the month a person was born in with their risk level from specific diseases. It found correlation between babies born in different months and the following diseases:
January - Hypertension, cardiomyopathy (heart muscle disease)
February - Lung and bronchial cancer
March - Cardiac failure, mitral valve disorder, arrhythmia
April - Angina
May - A lucky month with no increased likelihood of disease
June - Pre-infarction syndrome (severe angina)
July - Asthma
August - Another lucky month
September - Vomiting
October - Insect bites, STIs, chest infections
November - Least likely to develop arrhythmia, mitral valve disorder and lung cancer