IQ is very accurate to estimate the person's intelligence
the average score usually is 100 ...my swcore varies between 115 and 120 i was never very brave at school , my bro is 135 (above 130 means genius ) and my bro was awalys the first at school and he was the first at his whole university .
My sis 's IQ is around 100 ....she wasn't good at school as well my father
my mom's IQ is 135 like my bro's she was genius .
many studies proves that IQ Is related to genetic factors ....so some ppl are born average smart some are born genius ....some are born not very smart ...it's ALL about genetics .
You think Einstein would achieve anything if his IQ wasn't 150 ? baah hell no .