I have noticed that I try to get along well with a particular kind of people. They seem to be of varied professions, upbringings, cultures, countries, races, etc...but the affinity is very very strong. It lasts for a lifetime, they are my friends for life. I see some common things in all these friends of mine-they are honest, truthful, monogamous (or at least serially monogamous) and at some level, "reliable" to me.
I will assert here that this "honesty" which leads to life long friendships is genetic. I have a natural affinity for people like this. This is for both men and women alike.
When we don't get along well with someone-I believe it is also a "genetic" clash at a very fundamental level. These others surely find other groups of people with similar genes to hang out with, they are their genetic friends, but the point I want to make in this post is that our election of friends, and a partner, are GENETICALLY motivated, and not on other things. Nature dominates, Nurture is secondary for adult human beings.
You don't expect CEOs in suits and ties to hang out with people with more than 100 or more piercings on their body. There are exceptions, of course, but even our selection based on appearance and clothing style has a signature of genetic selection written all over it. It is safe to say that given no other information, you believe that your best friends will be people who will look or dress the most like you. Physical appearance is the easiest measure of similarity. Your phenotype is largely determined by your genotype.
Everywhere in the world I see this in action. People of the same kind stick together-and what do we mean by that? The only real similarity between two individuals is genetic. Animals do the same, as you might expect (we are a part of the group). When you walk out with your dog in the park, the dog reacts and responds to other dogs. It is interested in animals which look more like it is. In most cases I venture that the encounter is friendly; the dog may love you and everything; but would rather spend time with other dogs who it gets along well with (genetic affinity in layman's terms).
You see this with children. If you walk with your child in a mall she is interested in other children in the mall; not the adults. What's going on? The child is able to assess 'moving objects which are most similar to herself' and responds to them positively in most cases. That is genetic selection-you are interested in your look-alikes, your genetic clones, other living being who are like you.
This is the reason why humans of the same age tend to hang out together. You can argue that they are equal in maturity, have the same culture etc. but because even kids and dogs who have no idea about maturity and pseudo-scientific words like culture are attracted to their own kind, it is easier to explain everything by accepting the genetic similarity (which in most cases will be phenotype similarity as well) argument.
As a general rule-all individuals (includes animals) try to find other individuals who are the most genetically similar to them.
Consider a couple of other facts. When you see orthodox Jews in New York City, Sao Paulo or Buenos Aires, you are struck with how similar they dress. That dress is a signature of their genetic similarity, the genetic signature of their group (and consequently their difference from others around them). The same goes for Gypsies all around the world, or the Native American tribes throughout the Americas-from Canada to Chile. Or the cowboy-rednecks in the southern United States, or the much smaller Amish community in North US. These are groups of people who are called so because they preserve their culture (a word which is a social sciences word, and quite imperfect)-they way they dress, the music, the way they talk, their physical appearance, etc; but when your look at them as simply preserving their genetic group, it all makes scientific and biological sense, and becomes easier to understand. When I see these groups of people, or some aborigines in Brazil or India, I cannot help thinking that they really are a different species (sub-species) than me and my friends for all practical purposes-they are a different species than I and my friends. Some years ago I went to a private party-the people said hello to each other, and started drinking right away-without many words exchanged. I felt so awkward. Whenever you are with a group of people who seem to get along well with each other, and you feel like an outcast-you can be sure that there is a genetic similarity running among them, and you don't have that particular set of genes which makes them get along well with each other. I mean adults (let's say more than 25 or 30 year olds) and not children-who may not have a choice in selecting who they hang out or party with.
When a I see a Gypsy woman approach me for money, I am struck by how different she is from me. I could call her a different species. Same goes for orthodox jews, people with 20 piercings on their face, or 100 tattoes on their bodies, executives working in banks, insurance and other fluffy sectors. I can give you dozens of groups like this who I believe can be classified as a sub-species of humans. They are so different from me-that I don't mind thinking of them as a different species than me. I am sure the feeling is mutual-they think I am an ET.
I have no intention of disparaging any of the groups mentioned-it is this diversity in humanity which makes life interesting. As long as there is no violence and aggression between the groups, life goes on just fine-and you can appreciate all these different sub-species of humans and enjoy the various different activities they offer as a group.
One must be careful, therefore, to talk about humans. There are many different kinds-do you think a scientist at NASA has much in common with an aborigine in Brazil or Africa? Yet they are both called humans. It would be like me talking about primates and thinking that monkeys and chimpanzees and humans are one and the same thing. I see this sub-speciation occuring in human groups at all levels-in day to day life, we hang out with people of our own kind, genetically speaking. Mind you that appearances can be deceptive-there's more to genetic similarity than just the way you look, although that is a good first indicator. Just like based on looks alone your domestic dog is quite similar to a wild dog, but you down deeper and realize that they are so very different! Or how dogs of different colors and spots hang out quite fine with each other, but suddenly will kill another dog. Some of these fights are territorial, but in the end, it can all be traced down to genetic differences between the dogs who group together to kill the "new" dog. The same behavior is true for humans-in hostile tribes, a new individual is killed. We have come a long way in intermixing, we don't kill or imprison people from new countries and tribes, because somehow we as humans collectively are able to realize that there are things in common you might have with someone from a different race, country, or tribe, far overshadowing the common genetic characteristic of the race (or tribe or country). This is how intermixing first started-you could trust people from other tribes and found that you have more in common with them, to actually go out and marry into that tribe. Note that primitive tribes are still marrying within their families (brothers with sisters, cousins, etc). In general, the more primitive and closed a culture (or racial group, tribe, country) the more the marriage within the same family, or same race, same caste, etc. The freest and most open societies, like in Western Europe and South America, are less prone to marriages of this kind.
It is obvious that a human being like you and me can cross with any of these groups to form babies-but that doesn't mean that they are not substantially different GENETICALLY. Crossing is a poor way to define species-witness mules, asses, and tiglions. I would guess that if a human male is crosses many many times with a female monkey, in maybe a few hundred thousand crosses, a healthy baby will emerge, just like in the cases of a tiglion or a mule.
We must also note that as different as we look like from outside -let's compare a cow, a monkey, a mouse, and a human-the internal organs and structure are very similar. You are beguiled by the appearance of the skin and the shell-but we without a skin (scaled for size of course, by taking different age sample of these groups) the internal structure of all these animals is very similar, and can confuse even an able scientist). Darwin talked a lot about this in his works.
The whole advance in modern medicine is based on this-we test on mice and when it works we move to higher animals. The obvious truth there is that drugs function similarly on all of us-and that means that we are far more similar that you would like to believe.
I seem to have digressed from the original subject of this post, but , you will realize that it is eventually the connection between all these varied animals, and then the groups choosing the ones most similar to them (their genetic 'friends'), crossing with them, preserving the children, and eliminating the ones which are different from them (their genetic enemies, or not-so-good friends) , is how we are forming new species in all animals.
In humans, you may object-saying that we must cross within the same family (brothers marrying sisters) to be nearest in the gene pool- but it is not necessarily true that you are genetically the most similar to your sister. From large amount of data with humans I can safely say that family bonds are weaker than bonds formed between friends (based on genetic similarity is my argument). Of course, we should talk about adults here, not children; who are dependent on their families (let's say adults are all humans above age 25).
In mate selection, I see the same thing happening, the genetic affinity come really into play here. Your spouse or mate is an extension of your friendships. I believe there is a lot in common between your spouse and your friends, they are the same type of people. Furthermore, you are selecting who you mate with at a very fundamental level, and you can see some very clear patterns here, where it is obvious that you are choosing someone who is similar to you, but of the opposite sex (why that is I don't know. This is obviously for heterosexuals, I don't know how this works for homosexuals, but should be similar). Tall people hang out and marry tall people, dwarfs marry dwarfs, and it is striking to me how couples seem to be so similar PHYSICALLY speaking. This can easily be extended to other animals-and comes from the same base 'genetic affinity with someone like me'. For humans, it gets more complex and fun to watch mate selection-heavily tattooed people marry heavily tattooed people, for example (because their love for tattoos is a very clear and obvious way for them to express their genes, just like tallness or shortness). People with lots of piercings also marry other people with lots of piercings. The underlying cause is biological; what you are seeing is the effect of the real cause when you see people with similar physical characteristics pair together. Heavily tattooed people marry heavily tattooed people not because they like people with tattoos as you will hear everyone say (which is a statement which doesn't explain the causality involved); but because there is something in their genes which made them have so many tattoos in the first place, and they are looking for people who have these genes, and in their case, it is easy to recognize because the genotype is expressed in the phenotype by these people getting lots of tattoos.
This genetic affinity we have at the individual level, and by it's natural extension at the group level, is the reason, the cause, for racial discrimination. Most individuals are designed to prefer their own race, and will exclude other races. Only when a high measure of intermixing has occurred, as in Brazil or Central American countries, that you see people of "one race" begin to lose their majority and the majority becomes "mixed" or mulatto, as en Brazil. The intermixing is the cause of why racial discrimination goes away slowly. Why some people are not racists is more a surprise than why they are racists-how they became intelligent enough to realize that their outside physical appearance is not enough to determine their genotype in all cases-and that they can get along well with people who look substantially different from them (their own race). South America is hands down the most civilized and racially tolerant part of the world in that regard. A fraction of every race is designed to intermix, and why that is I don't know, but these are the ones who are able to realize that you have more in common with people of other races than your own race, or at least that race becomes a no-factor in friend and mate selection. Eventually this fraction begins to dominate the population in numbers, as in South America, and the area becomes non-racist.
This attachment at the genetic level for individuals, is the reason why nations take on a certain "character" of their own. It is in reality a genetic selection going on- e.g. people from France and Britain have been moving between the two countries for many hundreds of years, and it is natural that people of one type will huddle together-and u can see the characteristic French or British trait in a substantial number of the citizens of each nation.
I don't want to bore you with all these facts and observations without attempting to draw some conclusions from them which you can use in your daily life. The big one here is that if you don't click with someone fast, let it go-the incompatibility is at the genetic level. They may be a part of your family, may play soccer with you, go to the same University you go to, but you may not have much in common with them to call them your friend. Similarly, do not judge people on their habits, their professions etc.; try to keep and open mind and you will find that you will make excellent, life long friends in groups you never thought you could find compatibility. The real attraction is genetic, it is beyond race, it is beyond the habits you might have common with others. Because it is genetic, it is not ephemeral; it is strong and will stay that way all your life. I have used this idea to quickly form friends, and I am sure that these friends will be my friends all my life.
When you don't "click" with someone, walk away quickly and cut your losses. This is even more important in mate selection-where mistakes can be very painful. Don't force friendships and relationships on people; and don't expect people who you knew all of your life to be your best friends. You might make friends very fast in a voyage in Brazil or Germany. Don't be shocked if your sibling doesn't care much about you anymore; that is what makes you associate with other people quickly! It would be a contradiction if all your siblings and cousins were also your best friends; this is a characteristic of a tribal society, not a civilized country with millions of people and millions of possible (genetically compatible) friends to choose from.