Along with chromosome 8, chromosome 12 is also known to be important to brain development, function and intelligence. My own regional ethnic percentages on these two 'brainy' chromosomes (as reported using the newest GEDmatch Eurogenes K13 admixture proportions per chromosome) are:
Chromosome 8: North Atlantic (37.4%), West Mediterranean (27.1%), Baltic (23.4%), East Mediterranean (7.3%), Amerindian (6.4%), East Asian (0.9%) and South Asian (0.2%).
Chromosome 12: Baltic (47.4%), North Atlantic (31.9%), West Mediterranean (11.6%), East Mediterranean (8.1%), Siberian (0.8%) and West Asian (0.2%).
I've inherited 'brainy genes' from all over Eurasia and even from North America. Awesome.
The Baltic countries typically include: Denmark, Estonia, Latvia, Finland, Germany, Lithuania, Poland, Russia and Sweden.
The North Atlantic countries of Europe typically include: the Atlantic Isles (Great Britain and Ireland), Iceland, Belgium, the Netherlands, Norway, the central and northern regions of Portugal, northwestern and northern Spain (including Galicia, the southern Basque country), the southwestern and western portion of France (northern Basque country), western Scandinavia and northern Germany.
West Mediterranean countries and territories of Europe typically include: Albania, Bosnia and Herzegovina (both formerly part of Yugoslavia), Croatia, Cypress, France, Gibraltar (UK), Greece, Italy, Malta, Monaco, Montenegro (also formerly part of Yugoslavia), Slovenia and Spain.
East Mediterranean countries typically include: the Gaza Strip, the Golan Heights, Israel, Jordan, Lebanon, Syria, Turkey and the West Bank.
Amerindian includes the indigenous native tribes of the Americas.
East Asian countries typically include: China, Mongolia, North Korea, Singapore, South Korea, Taiwan and the Russian Federation through Outer Manchuria and Siberia.
Siberia is a vast region of Russia and northern Kazakhstan constituting all of northern Asia, extending from the Ural Mountains in the west to the Pacific Ocean in the east and southward from the Arctic Ocean to the hills of north-central Kazakhstan and the borders of Mongolia and China.
South Asian countries typically include: Afghanistan, India, Nepal, Pakistan and Sri Lanka.
West Asian countries (synonymous with the Middle East) typically include: Anatolia (Turkey, Cypress), Caucasus (Armenia, Azerbaijan, Georgia), Levant (Israel, Jordan, Lebanon, Palestine, Syria), Mesopotamia (Iraq, Kuwait), Persia (Iran) and the Persian Gulf (Bahrain, Oman, Qatar, Saudi Arabia, United Arab Emirates, Yemen).