To conduct the study, researchers from McGill University asked 78 women between the ages of 18 and 29 to fill out a questionnaire about their sexual behavior and other life factors before having them memorize random words and photos of faces, which were presented to them on a computer. The participants then looked at a mix of new and old photos and were asked to identify the words and faces that had previously been shown to them.
After analyzing the results, the researchers noticed an interesting connection: The women who reported having penile-vaginal sex more frequently were significantly better at remembering the words previously presented than the women who reported having less sex.
The researchers found no association between sex frequency and remembering faces, and they believe this might be because penetrative sex — versus other types of sexual stimulation — could help neurogenesis (a.k.a the growth of new brain cells) in the hippocampus, an area in your brain that is linked to word memory.
The study looked solely at short-term memory, but study author Jens Pruessner, PhD, says he believes "the long-term memory effects should be similar." And it gets better: Although this was not part of the study, Dr. Pruessner says sex may help improve other cognitive functions centralized in the hippocampus, such as spatial navigation (think: using landmarks to remember directions).
That said, these findings don't mean that hitting the sheets will give you a photographic memory. The study had several limitations, including the fact that it was small and the sexual behavior data was self-reported by the participants, so more research is needed.
One thing we do know? If you were looking for a good reason to make like Marvin Gaye and get it on tonight, this oughta do it!