Rubbish!
We humans are liberals when it suits us, or conservatives when it suits us. Or we can be both things at once. Those persons who are one way all the time are the fanatics and are in the minority. Most radical liberals and conservatives can't even define themselves without stuttering and becoming flustered. I would estimate that 97% of the people I deal with are fair and honest centrists. I don't hang around with radicals because they're scary, and boring.