To start with, I am not a sociologist. But as someone who has travelled a lot, I have been intrigued by this question. For example, Somalis share a common cultural background, customs, language and most are Muslims. These are important elements that many people consider necessary for forging and fostering unity among the population of any country. Yet, why is it that, at least in Somalia, elements of the population have been at war with each other for about two decades now and cannot seem to organize a government that the majority can endorse or support? While Somalia may be an extreme example of mutual animosity and antipathy among the citizens, variations of this include inter-tribal hostilities in the Sudan, Ethiopia, immigrant-settler conflicts in Plateau State in Nigeria and similar situations in other African countries. In contrast, there are also examples of people of various tribes being generally friendly and good-natured toward each other, as I have observed in Ghana, where I visit quite often. On several of these visits, I tried to find out why Ghanaians generally tend to be quite gentle or even patient to a fault.

Of course, there are many complex factors to unraveling this riddle, but I shall confine myself to a specific aspect of their history and leave the remainder to Ghanaians and other observers of this county to fill in the gaps.

It appears that, unknown to most Ghanaians, they have had a very long history of inter-marriage that continues to this day. The institution of marriage is probably the most sensitive level of a spectrum that spans from one extreme of intolerance by parents of their sons and daughters marrying members of other clans, tribes or races to the opposite of toleration and acceptance of intermarriages. Whether among Indians and Pakistanis (with their honour killings) or in the Americas, western or eastern Europe or wherever Europeans dominate or under so-called tribal conditions, it appears that people must first overcome this principal and most basic or sensitive social barrier. Then, other potential sources of societal barriers to people generally getting along with each other become benign or less important. As Ghanaians have often told me, relationships among them are sometimes so complex or unknown that the person you cheat or harm may eventually turn out to be some distant relation of yours or of someone else with whom you share social networks.  

I also found out two other interesting aspects of gene-pool mixing that make Ghanaians to the southern forest areas relatives of those in the Savannah zones to the north. For example, due to good reasons of evolution, the ancestors of the inhabitants of the forest zone to the south of Ghana originally had relatively smaller and shorter bodies, as can still be seen in the populations, especially in the mid-section of the Ashanti Region and those surrounding it. Similar pigmy populations still live in the rain forest zones of the Cameroons and the two Congos (DR Congo and Congo Brazzaville). However, due to the intensity of intermarriage in the Ghana population, heights and body sizes in the forest zone have increased remarkably.

The second gene-pool mixing was due to the slave trade of previous centuries. Most of these slaves, the ancestors of most African-Americans, came from the Savannah zone of the northern interior lands. They were herded into castles that served as trading posts that the Portuguese, Danes, Dutch, British and various European traders and administrators had established along the coast at Elmina, Cape Coast, Abandzi, Osu (now part of Accra) and other locations along the coast of what was then the Gold Coast. These Europeans picked whomever among the women that they wished to have sex. For the Governor of the castle at Elmina, the windows of his residence, two floors above ground level, opened and looked down into the female slave quarters. Part of this residence was where Christopher Columbus spent two nights, reorganized his sextant and later sailed to discover the New World of the Americas.

The slaves that became pregnant were never exported but were released into buildings that these Europeans constructed near these castles where they delivered their babies. One of such buildings is still at the original site, just outside the Elmina Castle. Nonetheless, resulting from the sexual activities of these European administrators and merchants, the children that they produced were the first in the history of the Gold Coast to attend schools in these castles and were later used for the beginnings of the Civil Service, the Judiciary, the commercial class, educators and other institutions of the emerging western-style modern state.