The study, by New York’s Stony Brook University and Harvey Mudd College in Claremont, California, polled 274 married individuals, a major newspaper reported.
Forty percent of subjects who had been married for over ten years told researchers that they were still “very intensely in love”.
Another 13.4 percent said they were “intensely in love”, and 26.2 percent agreed with the statement that they were “very in love”.
The feeling was defined by a combination of behaviours such as thinking positively about the partner, being affectionate with one another, sexual intercourse and general life happiness.
According to the study authors, their results counter the commonly-held belief that feelings of love decline over time.
This is even true for couples married well over a decade, it seems. While the findings showed a drop in very intense feelings of love for those married over 20 years, it rose back up to 40 percent for couples married over 30 years.
There were some differences between the sexes when it came to behaviour that represented intense feelings of love, however.
For men, thinking about their partner at all times was a key marker of a deep love, but the same was not true of women.
The authors also revealed that female participants, in contrast, linked those strong feelings to passion for “non-relationship factors”.