"Irish twins" is a term used to describe siblings born to the same mother within 12 months of each other. They are not literal twins from the same pregnancy but are so close in age that they often share a strong bond and experience similar life stages together. The term sometimes extends to siblings born within 18 months apart. The phrase originated in the 19th century as a derogatory label related to Irish Catholic immigrants in the US, who were stereotyped as having many children in quick succession due to limited access to birth control. Today, the term is used more lightheartedly to describe closely spaced siblings but may still carry some negative connotations, so it should be used with care.
