Culture and society
Gonds appeared to dress in a uniform way. Their garments were predominantly light-coloured, with straps about the waist, sleeves, and calves. Generally, these straps were a dark colour. However, Beta's white straps suggested there might be a heirarchy attached to the straps. (TV: The Krotons)
For some (apparently) considerable number of generations, the Gond were raised with one major goal: selection as a "high mind" by the Krotons. All Gond youth had to submit to a series of academic tests, and, if found to possess a sufficient level of intelligence, were allowed to serve the Krotons directly. This involved entering a special area of the Gond settlement completely controlled by the Krotons.
The general Gond populace was kept ignorant of the purposes of this selection until the arrival of the Second Doctor, Jamie and Zoe. They revealed that the "high minds" were actually being killed. Closer examination revealed this "special area" to be a Kroton spaceship, which was powered by thought. The "high mind" Gond were killed because their mental energy was completely drawn off as fuel.
Once the Doctor revealed the Krotons' actual purpose, the Gond rose up against their Kroton overlords and killed them. Thereafter, Gond society was allowed to develop without constant alien presence. (TV: The Krotons)