Being happy in your marriage might have less to do with chemistry between you and your partner and more to do with your genes.
Researchers from UC Berkeley and Northwestern University in the U.S. have found a link between relationship fulfilment and a gene variant, or "allele," known as 5-HTTLPR.
Everyone inherits a copy of this gene variant from each parent.
Researchers found study participants with two short 5-HTTLPR alleles were far more affected by the emotional highs and lows of their marriage (most happy when there was positive emotion, such as humour and affection, and most unhappy when there was a lot of negative emotion, such as anger and contempt).
Those with one or two long alleles were far less bothered by negative emotions associated with their marriage.
The study involved 125 married couples who have been part of ongoing research for more than 20 years.