1. Group hunting by Harris hawks (I had a family of them on my property in Chile - beautiful animals). Predatory birds are solitary hunters, right? Not the Harris hawk - it hunts in packs, with some corraling the prey and others making the kill-dive. And the kill is then shared by all.
2. Lions. Unlike the other great cats, they hunt as a team, and share the spoils with the entire family. And it is the females that do the hunting. The males, on the other hand, provide protection for the pride, that is their role.
3. Orca (killer whales). They also hunt as packs, taking turns diving deep under herring balls, bundling the herring with their expelled air (a bubble curtain), and letting others take passes through the herring to eat. They will also all turn to defend calves, and even will stay with a dead calf to mourn.
How are any of these behaviors anything BUT cooperation and a form of societal structure? In each case, individuals will put the needs and desires of other individuals first - cooperation means that sometimes you give up what you want, and you wait your turn.
if behavior like that exists in animals, then why not in people?
Well obviously it exists in people and animals. The question is whether it is consistent with the picture painted by Darwinians of people and animals.