Other People Often Aren't As Shallow As They Seem
People who aren't doing well socially sometimes feel they can't relate to anyone. One common complaint that flows from this is that they feel other people are dumb and shallow. If they see themselves as deep and intelligent in comparison, they naturally feel alienated.
Some people really are superficial and vacuous. I'm not going to argue that. Not everyone is though, and in my experience a lot fewer than you'd think. This article will offer a little defense of seemingly shallow people, and the supposedly vapid things they do.
There are many superficial traits that can make people seem more shallow than they are
I think a big problem with the "Everyone sucks, I have nothing in common with them" attitude is you can end up writing off lots of people before you even give them a chance. Many people who seem superficial do have "deep" interests or tendencies. The issue is their more surface features are easy to see, while their more substantial traits are hidden.
There are guys who seem like meathead jocks at a glance, but who read constantly and can easily hold their own in a discussion about economics or the Western Canon. There are women who seem like all they care about is makeup and clubbing, but are interested in philosophy and history. These people do have more "shallow" traits and hobbies, and they're the first thing you notice. If you never spoke to them in depth and just went on the stereotype their appearance conjured up, you wouldn't learn there's more to them.
Shallowness isn't an All-or-Nothing thing either. Someone could spend the day reading about soil erosion in third world countries then go out at night and get drunk with their friends. So be open-minded, don't be too quick to judge people, squawk, squawk, squawk.
Here are some factors that may make layered, intelligent people initially come off as dumbasses:
Some people are quite smart, but they have naturally scatterbrained, happy-go-lucky, or short-attention-span personalities and can seem way less together than they are.
Accent and style of speaking
Many accents have negative stereotypes associated with them. Someone could be a physics professor, but have an accent that instantly makes people think, "Wow, what a hick." In terms of speech patterns, some people have a fast, ditzy "Like, ohmygod, no way?!" style of talking that can mask their intelligence. Or someone could come off as dopey by overdoing a stoned, laid-back surfer inflection. Even the fairly common habit of using conversational filler such as 'like' and 'you know?' can make a bad impression.
Similarly, sum ppl naturllly write lke this lololol!!!1!, whether through email or text messages. And it's often not that they can't use proper spelling and punctuation when they want to, they just don't think it's important. Their mentality is more to fire off what they want to say and not worry about how it looks, since they figure it's still understandable. If writing correctly is important to us we can't help but see a poorly constructed sentence as reflecting a lesser intellect. More often it just indicates someone who's not as worried about that stuff.
The way they act when they're having a good time
The way people act when they're excitable and having fun can make them seem dumb and shallow as well. Guys can get loud and crude. Women can get shrill and hyper. Those are pretty natural ways to behave when people are in 'fun mode'. They may still be able to have a calm, rational discussion when they're in a different mood, and under different conditions.
Place in life
Many intelligent, complicated people go through phases in their lives where they enjoy going out and partying a lot, and generally seem as if they have shallow priorities. Eventually they grow out of it, for a while at least, and start to enjoy things that are more toned down and high-brow.
Their social circle's shared style or interests
Social circles can have a few common denominators that apply to every member. Maybe they all like X,Y,Z and their friendship revolves around that. Each member also has their own unique, more esoteric interests. However, since the rest of the group doesn't share these hobbies they may not feel any need to bring them up. It's not that they'd be ostracized, just that their friends wouldn't be that interested or able to have a good conversation about it. It's easier to stick to the topics everyone has in common. A group could all seem uniform on the surface, but deeper down there's a range of less-obvious worldviews and pastimes.
This effect also works in reverse and can hide someone's more mainstream interests. In a group that isn't particularly interested in sports, a member may watch half a dozen games a week on their own time, but not feel the need to mention it or draw attention to it through their appearance.
Lots of people have certain heavy, cerebral topics they'd love to discuss, but they've learned that doing so can get everyone riled up and lead to arguments. They decided a while ago that it was better to resist the urge to talk about things like politics or religion's negative influence on the world, because it's not worth the bad vibes that it can cause. They save those conversations the right time and place.
Not wanting to talk about a topic in certain settings
Similarly, someone may be fully capable of talking about a subject, but not feel it's appropriate given the circumstances. Like if you're at a wedding and try to chat with another guest about whether communism is a viable model for society, they may give you a bunch of one-word responses and then change the subject. It's not that they're too shallow to be able to have that discussion, they just want to keep it light and fun at the reception.
Style of their intelligence
Lots of people are smart and interesting, but they come across as pretty regular types, not refined intellectuals. I think some people can make the mistake of thinking someone is only smart if they like to discuss topics like logical fallacies and Game Theory. Not every brainy person cares to learn about those things.
Their fashion sense
Another thing that can hide someone's deepness is their style. Someone may dress or groom themselves in a stereotypically shallow way, because they like that particular look (though they don't necessarily identify with everything about the subculture that look is associated with), because they have to for work, or because that's how their friends dress, and they just went along with it.
Their thoughts are concealed
It's easy to think other people are less deep than you because you only see their surface behaviors. You, on the other hand, have access to all your hidden inner thoughts, many of which are profound and insightful. Couldn't other people have just as rich a mental life as you? And couldn't people look at you in some situations and conclude there isn't much going on in your head? If someone just saw you going about your weekly routine from a distance, how much would they really know about you?
They seem pretty content
Don't think you have to be angsty, cynical, and preoccupied with existential questions to be deep, or that anyone who is happy, carefree, and fun is shallow in an "ignorance is bliss" kind of way. A lot of people go through a phase where they're bummed out and ponder the meaning of life, but they work through it, find answers that satisfy them for the time being, and become more cheerful again. That they're happy now doesn't mean they're a peasant who never thinks about bigger issues.
They have good social skills
Some people go so far as to think anyone who seems comfortable with social interaction, and who is chatty in a group, is automatically a brainless sheep. They think deep people can only be wretched social outcasts. Yes, sometimes if you're very bright it can put up a wall between you and other people, but that doesn't mean everyone who's sociable is a dummy.
In moderation shallowness isn't inherently bad
If you're vapid to your core that's no good, but in reasonable doses shallow things are fine:
Shallowness is part of the lighter side of socializing
There are different modes people can socialize in. Some forms of supposed shallowness are part of that fun, silly side of being with people. It isn't better or worse than being reflective and serious, just different. You can't operate in one social style all the time, just like you're not always in the mood to watch an intense, draining 3-hour drama when you pick a movie. If you lean a little too much toward your logical, serious side consider adding some lighter elements to your personality to balance things out.
Shallow things can be fun
Lots of people love cheesy, gratuitously violent video games, empty, shiny action movies, or websites full of throwaway, puddle-deep humor. They're seriously lacking in substance, but they're fun. Nothing wrong with having fun.
Shallow things can be a guilty pleasure
Lots of people realize that some of the things they like are fluffy and trashy, but they're a guilty pleasure, so why not? People will listen to disposable bubblegum pop because it's catchy. They'll watch reality TV or daytime talk shows because of the train wreck appeal of the people on them.
In the same vein, some people are into things that they acknowledge are an illogical waste of money, but do them anyway because they like it and get some payoff. Some women completely realize they spend too much on makeup or purses, but that's their thing and they feel it makes them look good. Maybe you've bought a high-end action figure, neat sculpture, or replica sword to display in your room. Some people probably didn't see the point of those purchases, but you only live once and bought them because they appealed to you.
Shallow people can be fun
Even if you may never want to have a long, involved discussion with them, more vacuous people can still be entertaining enough to idly chat to, or to keep you company when you go out.
Some shallow things aren't really shallow at all
Some things that you may label as shallow and mindless are actually quite complicated. Sports and video games often get written off, but they're full of nuance and strategy. Some TV shows or comics can have deeper plots than many people give them credit for at a glance.
Some shallow things have positive benefits
A guy who works out just to look better is still staying in shape. A woman who cares a little too much about clothes and her appearance still looks good. Someone who plays MMORPG's for hours a day is still probably honing a broader life skill or two, like learning how to work with a coordinated team.
Some shallow things just work for other people
Sometimes we can look down on the "shallow" lifestyle or life path other people take. Just because it may not appeal you, it doesn't mean it isn't rewarding to them. For example, you may think a 9-5 job, a house in the suburbs, and 2.2 kids is soul sucking, but other people may find it fulfilling.