Singapore and Hong Kong are warm and tropical and they have highest average IQ in the world.
Spain is warmer than Ireland but Spain ranks equal 9th vs Ireland 15th
Australia is warm and rank equal 9th
Bhutan is a cold mountainous land yet they are well down in the rankings at equal 27th.......
Too many examples where warm temperatures have higher IQ - this so called study is easily falsified I think. Temperature does not determine intelligence.
