If you remove the requirement for "strongly opposed belief", this explanation neatly dodges the standard objection to psi that if something so obviously evoluti

If you remove the requirement for "strongly opposed belief", this explanation neatly dodges the standard objection to psi that if something so obviously evolutionarily adaptive is possible, why doesn't everyone have it? In this explanation everybody does have psychic power, it's just that some are aimed purely at shutting down other powers. In a zero sum competition, preventing your opponent from gaining an advantage is the same as gaining an advantage for yourself. Does anybody know of any fiction where humanity is split into a stable equilibrium of psi and anti-psi?