Stimmt alles, aber wo ist da jetzt der Zusammenhang zum "dummen
Vegetarier"?

zum Beispiel hier: http://www.second-opinions.co.uk
Siehe da insbesondere beim Menüpunkt "Vegetarian"
und da z.B. den Artikel "Vegetarians have smaller brains" ( http://www.second-opinions.co.uk/vegetarians-have-smaller-brains.html#.XNHcmU7VKV4 )
Zitat:
Since the advent of agriculture, there has been a worrying trend as our brains have actually decreased in size. A recently updated and rigorous analysis of changes in human brain size found that our ancestors' brain size reached its peak with the first anatomically modern humans of approximately 90,000 years ago. That then remained fairly constant for a further 60,000 years.[11] Over the next 20,000 years there was a slight decline in brain size of about 3%. Since the advent of agriculture about 10,000 years ago, however, that decline has quickened significantly, so that now our brains are a further 8% smaller. That is a total of 11% smaller than at their peak size.