We always want what we can't have. And maybe that's why, according to a Men's Health survey of 1,000 American women, the number-one desired skill in a man is being a good listener.

Unfortunately, a third of women say their pets make better listeners than their partners do, found a 2010 Associated Press poll. More than half of men agree they're terrible at listening ... unless it's listening to their bros talk about sports or tales of getting laid. (Ironically, men who rate as good listeners are more likely to satisfy women in bed, according to researchers at the Johns Hopkins Bloomberg School of Public Health.)

What explains this discrepancy? It's partially biological: Men only process language with the left side of their brains, whereas women use both left and right. And it's cultural as well, says Dr. Deborah Tannen, a professor of linguistics at Georgetown University and #1 New York Times bestselling author of "You Just Don't Understand: Women and Men in Conversation."

She told us what's really going on when a dude asks, "Sorry, did you say something?"

Boys and girls often learn to communicate differently with their closest friends -- but as adults, we expect our partners to fill that role.

Dr. Tannen: "Research on children shows that use of language ... in creating friendships works differently [between genders]. Girls tend to have a best friend [and] spend more time talking, and the talking makes them best friends. Boys tend to have a bigger friend group, and the best friend is the one they do the most with.

"This grows into very different ways of using language growing up. When they get older, girls expect a boyfriend to be the new and improved version of their best friend -- they’ll tell each other everything, and that’s what makes them close. What ends up happening, since boys don’t have that experience, they don’t end up being what the girls expect."

Which may explain why texting leads to so many arguments.

Dr. Tannen: “A student in my class said, 'I’m sick and tired of seeing relationships break up because girls send long text messages, and guys respond with one word.'

"Girls [tend to] send more texts and longer texts about what’s happening in their lives; boys [send texts] to get together, but not the chatty texts so much, and they don’t understand the point of the details. Girls will take a picture of what they’re eating or [to show] ‘This is where I am,’ and the boys wonder, 'What are you supposed to say to that?'

"[Boys] playfully insult each other, which girls may take literally, since they’re less likely to insult each other playfully -- or at least not as aggressively as boys do. ... It’s very easy to be misunderstood when you don’t have facial expression, tone of voice. [Young people] know that you do have to be extra careful with what you’re receiving and interpreting."

Topics that build closeness between women don't necessarily work that way for men, which can make it seem like guys don't care.

Dr. Tannen: "The ‘troubles talk.’ A lot of girls will talk about problems as a way of being close to the person they’re talking to. A lot of guys don’t want to talk about problems. [They think] it makes you seem weak, and why wallow in it? You already went through it; why go through it again?

"To women, that’s what makes us close; we talk about problems to feel close. Guys want to fix it. From [the male] point of view, why else would she tell you? It’s going to make you crazy to hear, ‘Don’t give me a solution, just listen.’

"Very early on, I had a guy tell me, ‘When my best friend had a problem, I didn’t talk about it [with him], and [my wife thought] I let him down -- but I was there for him.’ [Men] don’t have to talk about it."

Men and women also tend to differ in our physical communication.

Dr. Tannen: “A fascinating difference is that girls and women look at each other when they talk, but men sit at parallels and look around the room -- but they are listening. Girls and women often mistake 'you’re not looking at me' as 'you’re not listening to me.'

"Once they [mutually] understand there is this difference, the guys may say, ‘I’ll try to look at you’ [and] girls will say, ‘Oh I understand, you’re still listening even though you’re not looking...’ The important thing is, it's a [social] pattern, not an individual pathology or failing."

If he's a totally different (and better) conversationalist in public than in private, there's a reason for that.

Dr. Tannen: “Telling what happened during your day -- for him, it’s not that interesting. He’ll say, ‘Nothing much.’ But [you may] go out with another couple, and he’ll regale the audience with something funny that happened. And she says, ‘Why didn’t you tell me that?’

"From his point of view, you don’t need to tell stories to your partner or entertain [her], but when you’re in a group, you need to use any story you can find to take center stage, to get the respect you feel you need.

"[Boys] use talk to negotiate their status in the group. The high school boy will give orders, boss the other boys around. Boys may boast about what they’re good at, but girls don’t [usually] like girls who seem to boast. Girls aren’t as obvious about it."

These gender-based behaviors seem to be persistent, even as society has shifted in other ways.

Dr. Tannen: “Way back in 1990, I remember finding a little study that the biggest complaint about relationships from women is ‘he doesn’t listen.’ And now, many years later ... it’s the same thing.

"We do see a lot of change in other arenas. Obviously girls and women get to do things they couldn’t do before -- there are more opportunities; girls aren’t being told ‘you can be a teacher or a nurse and that’s it,’ as I was -- but these differences in the role of talk and relationship seem to have not changed.

“It is important to say, this isn’t everybody. Kids can hear these descriptions of patterns as if they were [universal], and that’s not it at all. There are cultural differences that are overlaid on this. ... In Ireland, there’s a cultural 'gift of gab.' Germany seems to be a culture where there’s a negative value placed on too much talk about nothing."

The good news: Guys can become better listeners if they work at it ... and so can women.

Dr. Tannen: “You can come up with any compromise you want, any adjustment you want. We’re not talking about individual failings or failings of the relationship; we’re talking about widespread failings of [each] gender.

"Men, listen to the problem even if you don’t want to. And then she listens to the solution, which she doesn’t want to hear. There’s no reason [only one of you] makes the adjustments. ... We all filter out some things and not others; it’s not necessarily true that women listen better and remember more -- it’s about what they’re listening to, and who said what.

“I think people are happiest when they feel understood, and nothing is more hurtful than thinking, ‘Here’s the person who knows me the best, and [he or she] doesn’t understand me...’ So I’d say anybody who’s aware of these style differences and finds a way to accommodate them is probably going to wind up less frustrated."