Narrator: This is Science Today. A lot has been written about dreams and what they might symbolize. Psychologist Virginia Tonay of the University of California, Santa Cruz says that from a psychological point of view, dreams have a very practical function: they're our way of working out what's bothering us, even if we're not conscious of what those things are.

Tonay: I see dreams, the importance of dreams, as being showing us feelings that we have that we're not necessarily aware of, and helping us to connect the feelings that we're having now with other situations in the past.

Narrator: Tonay says that all over the world, in every culture, men and women have differences in the way they dream.

Tonay: Men tend to have more aggression in their dreams than do women, all over the world, and women tend to have more friendliness in their dreams than do men. Men also tend to have way more men in their dreams than do women. Women tend to have an equal number of men and women. Because men tend to be more concerned with other men typically in life. Men tend to have fewer emotions too, in their dreams, than women do.

Narrator: For Science Today, I'm Steve Tokar.