A new study has said that you can blame your serotonin levels for being a crybaby.
Frederick van der Veen of the Erasmus Medical Centre and colleagues have found that due to the differences in the neurotransmitter some people are more likely to cry in emotional situations than others.
The researchers gave 25 female volunteers a single dose of either paroxetine - a selective serotonin reuptake inhibitor (SSRI) that briefly increases serotonin levels - or a placebo.
Four hours later they were asked to watch one of two emotional movies: Brian's Song, to see the extent to which certain scenes had made them cry.
On another day, the women watched the second film with their treatments swapped over.
"It didn't matter which movie they saw, we saw a strong and consistent effect of paroxetine," New Scientist quoted van der Veen as saying.
"Higher serotonin levels lead to less crying," he added.
Although SSRIs are used to treat depression, their mood-boosting effects do not normally show up for around six weeks.
The women reported no change in mood in the current study.
"We're looking at the direct effect of a single dose of paroxetine," said Veen.
"Our understanding of the neurobiology of crying is fairly limited," said Christopher Lowry of University of Boulder in Colorado.
"It makes sense that it is tapping into circuitry involving serotonin," he added.
The findings were discussed at the forum of European Neuroscience in Amsterdam.