When Napoleon Chagnon went to Venezuela to visit the Yanomamo he was greeted by spears and bows pointed at him. Napoleon was in a lot of shock because of this unexpected welcome.
The Yanomamo were known as the "fierce people". Chagnon stated that what impressed him the most was the importance of aggression in their culture. The Yanomamo would beat their wifes, pound their chest to dueling and organized raidings to ambush and kill men from enemey villages.
Napoleon talked about how everything smelled bad and how everyone was filthy and nasty, but within a week he was the same as them being filthy and smelly.
Where's my steel?
When Napoleon Chagnon had to prepare a meal, he describes how just oatmeal took forever. He goes through the details of preparing it and says when he completed the meal it was almost lunchtime. He would only eat once a day.
The Yanomamo would always beg for his food so he started eating peanutbutter which looked like animal feces. He would tell them it was cow dung so he wouldn't have to share his food.
The Yanomamo would give Chagnon plantain seeds that were easy to eat, but in exchange they wanted steel tools which he could not give.