Thanks Susan. On reflection most of what I had been thinking was racism may actually be zenophobia, or even just not being from a multicultural environment so not sure how to behave when cautious about someone who is different.

Caution and/or aggression when faced with the unfamiliar is widespread amongst non-human vertibrates. It may be something that we all have to learn to deal with in ourselves and with which some cultures offer more support and reinforcement than others.

I am sure I learned at schools that west African slaves were mainly bought from slave traders, the payment being with goods from Europe. I suppose that may have been a lame attempt to throw some of the responsibility back to Africa, but that doesn't mean it was not true.