In much of Africa, it is possible to recognise the influence of recent social and economic history in the way people act. If you didn't know that Ghana had social stability and comparatively equitable growth, meeting people around the capital Accra would give you that impression. If you didn't know that South Africa was tough, inequitable, and economically advanced, thirty seconds in Johannesburg would lead you to that conclusion.
In Rwanda, I find it much more difficult. The capital, Kigali, is quite pretty, and quiet, with hospitable and non-avaricious people. The extreme violence of the 1994 war is only superficially suggested the unusually high number of amputees. Partially it may be because of Rwandan resilience; partially because there is perhaps no obvious way in which it could manifest; partially because I am not skilled enough to recognise the effects; partially because the experience is utterly beyond anything I have known.
In Johannesburg, the gestures and speech of the residents are recognisable to anyone who has lived in a large city, although even experience of a major Western city may leave people unprepared for the intensity of Jo'burg. The Rwandan capital Kigali, and the southern university town Butare, a few dozen kilometres from active war zones and threatened by military spillovers from them, just seem peaceful. Butare is like places in almost every country, with tracks leading to other similar towns, and a few buses waiting outside a cafe and some shops before carrying passengers elsewhere, whilst Butare mothers and grandmothers with babies wait only for some charity.
It's been a few years since I visited, so maybe it is easier to read now.