When you are intensely and passionately involved in a relationship, you may not have much time for others; a new study has numerically quantified this observation.
Two close pals is the average price you pay for falling in love, Oxford University scientists have discovered.
The researchers asked people about their inner core of friendships and how this number changed when romance entered the equation.
They found the core, which numbers about five people, dropped by two as a new lover came to dominate daily life.
"People who are in romantic relationships - instead of having the typical five [individuals] on average, they only have four in that circle," the BBC quoted Robin Dunbar, a professor of evolutionary anthropology at Oxford, as saying.
"And bearing in mind that one those is the new person that's come into your life, it means you've had to give up two others," Dunbar added.
In the study, Dunbar and colleagues questioned 540 participants, aged 18 and over, about their relationships and the strain those relationships came under when a new romantic engagement was started.
The results confirmed the widely held view that love can lead to a smaller support network, with typically one family member and one friend being pushed out to accommodate the new lover.
"The intimacy of a relationship - your emotional engagement with it - correlates very tightly with the frequency of your interactions with those individuals," said Dunbar.
"If you don't see people, the emotional engagement starts to drop off, and quickly.
"What I suspect happens is that your attention is so wholly focused on your romantic partner that you just don't get to see the other folks you have a lot to do with, and therefore some of those relationships just start to deteriorate and drop down into the layer below," Dunbar added.
The research, which has only recently been submitted for publication, was presented to the British Science Festival at Aston University.