From a Netscape Channels article:

Why Men Don’t Want to Talk at Night
What IS he thinking? After a hard day, he’s thinking he’d rather surf with the TV remote than talk to his lady love. And don’t nag him about the shoes he dropped on the family room floor or the clothes he left on the bedroom floor. He doesn’t even notice them.
That’s the word from social philosopher and author Michael Gurian, who claims that men are not lazy, sexist, or pigheaded. Instead, the male psyche is radically different than the female psyche due to distinct and profound biological differences in their brains.

Drawing on two decades of neurobiological research, as well as anecdotes from everyday life, Gurian reveals the deepest secrets of the male mind in his new book, “What Could He Be Thinking? How a Man’s Mind Really Works.”
While culture is important, Gurian maintains that the biological differences in the male and female brains explain just about everything that puzzles women about the opposite sex:
* It explains why men have such a thing about cars.
* It explains why he doesn’t see the dust on the furniture–or realize it needs to be dusted.
* It explains why he won’t let go of the TV remote.
* It explains why he thinks mowing the yard is more important than vacuuming the carpet.
* It explains why it’s difficult for him to talk when he gets angry.
* It explains why he can remember all the pitchers’ names and World Series scores, but not the conversation you had with him yesterday.
* It explains why he puts so much of his identity into his work.
* It explains why romance isn’t as important to him as it is to you.
* It explains why he won’t talk to you at night.
This is the big difference that explains it all: The male brain secretes less of the powerful primary bonding chemical oxytocin and less of the calming chemical serotonin than the female brain. Instead, the male hormones that bathe the brain are testosterone and vasopressin, which make him seek competitive, hierarchical groups to prove his self-worth and identity.
What does that mean in practical terms? While women find it relaxing at the end of a hard day to get involved in an emotional, touchy-feely conversation, the male brain just wants to zone out. And what better way to do this than use the TV remote control to mindlessly surf from channel to channel.
“The science has been crucial. Wherever I go, I start by showing PET scans and people can see for themselves the differences between the male and female brain,” Gurian told Reuters. “I think that alters life and marriages.”
He dares to suggest that men will never be able to meet all of women’s expectations. “Popular culture focuses so much on trying to get people closer. Most people believe that marriages break up because men and women are not close enough. But what I am learning about the brain leads to the idea of intimate separateness, in which the brain seeks less intimacy at times.” (Emphasis mine)
Here’s the takeaway, ladies: Instead of asking, “What IS he thinking?” you should be asking, “What COULD he be thinking?” Just don’t ask him that question at night.