--According to a new study from Bristol University in England, when women drink coffee, it gives them a temporary boost in brainpower.  When men drink coffee, it has the opposite effect.

--In the study, some men and women tried to do tasks like puzzles, negotiations, and memory challenges after drinking regular coffee, and some tried to do them after decaf.

--Men had a lot more trouble with memory and decision-making when they were ratcheted up on caffeine compared to when they drank decaf.

--Women did better on all of the tasks after drinking regular coffee.

--The researchers say they're not exactly sure why drinking coffee has opposite effects on the genders.