Why are guys so un-emotionally responsive?

I'm not an expert but I'v been around the block, so to speak. I'm almost 40 and have had 5 relationships with men lasting over 2 years each. 2 were common law, 1 was a fiance and 1 is now my husband. Some men are different than others. Some are more open emotionally, but even so...my husband is the most emotionally responsive man I know, but he STILL isn't as emotionally responsive as my sister or my best female friend. I'v read that it's because mens brains are wired differently. They just don't "get it". Women have more connections between their left and right side of their brains. Women also have more activity on a day to day basis in their brains as seen on a brain wave scanner (MRI?) This obvioulsy doesn't mean that men are not as smart as women, but that men are able to literally have nothing on their minds, whereas women are always thinking of something. REad up on the internet somewhere about this, it's very interesting and will help you to understand why men can be so exasperating to us women. The best thing to do is laugh at it, don't expect much, and always have good female friends.