Why and how did African reactions to Europeans and to the slave trade vary?

There were varied reactions towards Europeans, and Slave trade which varied from one region to the other. In West Africa for example, during the transatlantic slave trade, many Africans turned to the trade to expel their opponents or to garner profits. While in East Africa, some communities resisted slave trade by attacking trade caravans. European arrival, on the other hand, was welcomed through resistance, collaboration, and mixed reaction. In Kenya, some communities such as the Agikuyu resisted through a militia group known as the Mau Mau due to land alienation, forced labor, and kipande system. While some an ethnic group such as the Maasai collaborated the British for favors and protection.