How does "be altruist to those who are similar to you" evolve?
This is an important question in evolutionary biology, but you need to distinguish the biological terms 'altruism' vs 'cooperation'. 

Altruism in biology means giving up your chance to reproduce so that someone else can more readily.  This is not like a gorilla troop, where only one male breeds, and the rest contribute to mutual security.  A more typical example is a honeybee or an ant, where the vast majority of the hive have no ability to reproduce at all.  This happens in animals, but is relatively rare. Its causes are currently the subject of intense debate but as far as I know, the only cases are where you do this for others who are genetically similar to you.   That logic sort of plays out as you say: "My brother has kids, why do I need to have any? I'll just help out a little bit there."

Cooperation includes forming groups for mutual safety and increased competition for food resources are why you might vote or schlep down to the DMV to get a drivers license when simply getting in your car without might be just as good most of the time.  

Cooperation is incredibly common in biology.  It even happens between species.  A dolphin helps a ship navigate submerged rocks, symbiotic bacteria in our gut help us digest food, but also get enough to live and reproduce.  The benefit is always win-win in such situations.  

To understand how cooperation occurs spontaneously, one of the best experiments to look at is the Prisoners Dilemma experiment.  If individuals are in a situation where you are likely to see each other again later (like a society).  The most successful ones are the ones who treat each other reasonably well, even if you do look out for less reliable types.  Why do people from Northern climates have strong hospitality traditions?  "Today you (are in trouble) tomorrow me."  As the saying goes.

There are individuals who are not cooperative, but the selection forces are positive enough that those folks will regularly disappear from the group, while more cooperative types will become more numerous. 

This is a significant selective pressure that you can train robots with very simple reward mechanisms to cooperate.  http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.144.2881