2º. The living in fixed habitations is more favourable to the existence of slavery than nomadism.
3º. Slavery is most likely to exist among men who live in rather large groups.
4º. Where food is abundant and easy to procure, slaves can be of more use than where food is scarce; in the latter case the slave, to use Spencer’s words, “is not worth his food.”
5º. The preserving of food furthers the growth of slavery.
6º. Commercial tribes, especially those that carry on a trade in manufactured goods, have more use for slaves than others. We must, however, bear in mind that trade, even among savages, does not seem anywhere to be altogether unknown.
7º. A high development of industry also tends to further the growth of slavery. The instance of the Eskimos, however, shows that industrial tribes do not always keep slaves.
8º. Where wealth exists slaves are more likely to be kept than where wealth is unknown.
9º. Where subsistence is dependent on capital, slaves are not wanted.
10º. Where only highly skilled labour is required, slaves cannot be of any use.
11º. Female labour may in some degree serve as a substitute for slave labour (as in Australia). But where women enjoy much consideration, the men sometimes procure slaves in order to relieve the women of a part of their task, especially where the women perform productive labour.