Truth is entangled, and who gets to mate with whom is one of the biggest truths in human social interaction -- because mating behavior is very strongly selected by evolution. If you close your mind to the truths about human mating behavior, you'll mess up your entire map of human social interaction.
If we are going to develop rationality to the point where we see an increase in uptake of rational thinking by millions of people, we can't just ignore massively important parts of real-world human behavior.
I have a question, since you seem to know a lot about human sociality. What exactly is wrong with handling the dilemmas you describe by saying to the other humans, "I am slightly more committed to this group’s welfare, particularly to that of its weakest members, than most of its members are. If you suffer a serious loss of status/well-being I will still help you in order to display affiliation to this group even though you will no longer be in a position to help me. I am substantially more kind and helpful to the people I like and substantially more...
Followup to: Do you have High-Functioning Asperger's Syndrome?
LW reader Madbadger uses the metaphor of a GPU and a CPU in a desktop system to think about people with Asperger's Syndrome: general intelligence is like a CPU, being universal but only mediocre at any particular task, whereas the "social coprocessor" brainware in a Neurotypical brain is like a GPU: highly specialized but great at what it does. Neurotypical people are like computers with measly Pentium IV processors, but expensive Radeon HD 4890 GPUs. A High-functioning AS person is an Intel Core i7 Extreme Edition - with on-board graphics!
This analogy also covers the spectrum view of social/empathic abilities, you can think about having a weaker social coprocessor than average if you have some of the tendencies of AS but not others. You can even think of your score on the AQ Test as being like the Tom's Hardware Rating of your Coprocessor. (Lower numbers are better!).
If you lack that powerful social coprocessor, what can you do? Well, you'll have to run your social interactions "in software", i.e. explicitly reason through the complex human social game that most people play without ever really understanding. There are several tricks that a High-functioning AS person can use in this situation: