Qn: "Are traits such as arrogance hereditary? I see some communities labelled so"
Your short question is in reality two issues rolled up and presented as one. On the one hand, you seek to know if individuals inherit certain traits such as arrogance. On the other, you seek to know if whole communities can be differentiated on the basis of characteristics such as arrogance.
Within the first issue that you raise are a number of threads that one could follow. For example, to what extent do people inherit their values from their parents, and related to this, what is the effect of the environment on the development of values. This is an age old question whose lazy answer is that both are important. Somehow I don't think you will accept this answer and so we must delve deeper into the issues that you raise.
When you meet a kind, honest, and fair person, is that a reflection of the genes from his parents or is it more a reflection of the fact that he was brought up in a seminary? To make your seemingly simple question more complex, you also want to know if there is something that is typically English and defines them as opposed to the Germans, and also that differentiates them from Nigerians and also from Kenyans. Related to this is the question of whether one can tell a Teso from a Taita by the traits that they display. Are Taita more or less aggressive than the Teso and if they are, is it because of their genes or is because of something else?
As the plot thickens, we must now try to see if Kenyans and Tanzanians have traits that define them. First a little history lesson. At independence, Tanzania went the socialist “ujamaa” route while Kenya went the direction of free enterprise. Is that because Kenyans have traits that set them aside from Tanzanians or is it because founding presidents Kenyatta and Nyerere had different outlooks to life? What about the more recent difference in approach to the coronavirus pandemic. Kenyans went the route of limitations of movement and aggressive reduction in movement while Tanzania adopted the stance of continuing to work, or simply “chapa kazi”. Are these differences due to identifiable genetic traits? Most unlikely.
Historians will tell us in time which approach had the greater effect and in which way. That however is not your question. You want to know if the two people have different inherent traits that tell them apart! As you can see your simple question does not seem to have any simple answers.
Now for some lessons in science to see if some light could come from that direction. In brief, heritability is a statistic that is used to estimate the degree of variation that is due to genetic factors as opposed to the variation due to the effect of the environment. Note the key word here is that it is an estimate (not exact value). Given that it is an estimate then one has greater room to ponder the issues involved.
For example, we know that identical twins inherit identical genetic material and that any subsequent differences we observe would most likely be due to the differences in the environment they were brought up in. If for example one is significantly shorter than the other, one may speculate about malnutrition in childhood. If one failed to achieve full academic potential the poor learning /teaching environment might be to blame.
So, what are some of the behavioural traits that we inherit from our parents? The jury is still out on the exact characteristics but some mental disorders do seem to run in families. The most obvious are Bipolar mood disorder, Schizophrenia and Attention Deficit Hyperactivity Disorder (ADHD). There are some other personality traits that seem to follow the same line of inheritance. Fairness, reliability, helpfulness and sociability might follow similar lines of inheritance but there is no doubt that the environment that one is brought up in plays a crucial role.
Interestingly for all of us, the situation is more complex than that because, most people inherit both the genes and the environment. Naturally, only a minority of identical twins are brought up in different homes! As though that is not enough complexity, different traits have different levels of heritability for example eye colour is more heritable than behaviour.
As you can see, what on the face is a simple question, has taken us through science, history and politics without any clarity of the true nature of the answer to your question. Perhaps a good if not altogether lazy answer might be, it really depends on many factors, some that we know and others that are less clear.