I really like the theory of Evolution because of its simplicity.
I think if there had to be a “theory of everything” for explaining human behaviour, Evolution would be the best fit.
One strong piece of evidence is the existence of genetic algorithms.
Nobody would ever write a “Historical Materialist algorithm”,
where an optimal strategy to a game is developed by simulating the agents gaining class consciousness.
Or a “Freudian algorithm” where agents optimize by resolving Oedipal complexes.
How would you even do that?
Appendix
A genetic algorithm is a program that creates a bunch of agents that each play a round of a game.
Each agent has a different strategy and is awarded a score of how well it played.
After each round, the top 10% (or some other threshold) reproduce and the rest die.
So the next round will contain only copies of the best performing agents from last round.
Over time this yields an agent that has a good strategy to play the game.
Here’s a cool example of a genetic algorithm being used to learn how to play Super Mario.