There is some truth to the role of climate.

With some exceptions, notably Central America and the Andes, early civilizations seem to be highly correlated with plow agriculture, which in turn implies a hydraulic civilization with its canals, dikes, and other cooperative water control structures. It is very difficult to otherwise generate the food surpluses which lead to cities, crafts, and literacy. The use of the plow implies grains and soils suitable for those activities, which in turn leads us primarily to the temperate zones, particularly, river valleys such as the Nile, Indus, Yellow and Tigris/Euphrates.

On the other hand, the analogy can also be abused. I had a high school Civics teacher who constantly harped on how the Northern European races were superior because their harsher climates made them work harder and smarter for food and shelter, while Southern Europeans and Africans were clearly inferior because the climate was milder and food could just be plucked off the trees. When I pointed out that Southern Europe included Greece and Rome, and Egypt was further South still, he stopped bringing the subject up. After I pointed out the Northern Europeans were painting themselves blue and dressing in animal skins thousands of years after civilization was invented elsewhere, he stopped speaking to me altogether.

Cultural geographers are still divided as to the role of place on the development of civilization. The two camps are the diffusionist (everything was invented once and spread about later) and the independent invention school (the same ideas occur to different people in different places at different times). The truth is probably a little of both, and which is the dominant factor is strictly a matter of interpretation. There probably is no "correct" answer.

Incidentally, my high school Civics teacher was not necessarily a narrow-minded bigot, I've read those same ideas elsewhere, propounded by people who should know better. As unbelievable as it may appear to us today, he may very well have been formally educated that way. In my opinion, the total time between the first settled agricultural communities and the present (about 10,000 years), isn't long enough for biological evolution to have been able to differentiate
populations geographically, by intelligence. I suspect human intelligence may be too complex an attribute to be selected for so quickly in a species with such a long lifespan.

On the contrary, if anything, the existence of a sheltered organized community with food surpluses and technology should offer advantages and protection to the intellectually challenged which would not be available to hunter-gatherers. I think humans stopped being selected for intelligence once they settled down and started farming. If we could magically bring a few hundred Cro-Magnon babies to our time and raise them with urban families, I wouldn't be surprised if their average IQs were a few percent higher than our present population's. For the same reasons, I believe average human intelligence is on a path of decline. At best, we may be as smart now as we're ever going to get.